React sync for revisions ab4280b...ad9544f

Reviewed By: bvaughn

Differential Revision: D7256390

fbshipit-source-id: 9fe1324da93cb8f4a7f478e1037944774b9b95ff

Libraries/Renderer/REVISION

@@ -1 +1 @@
-ab4280b3e98dbb97d3e753083dab19879167c3f5
+ad9544f48e58f2599a8ea0de1e9f4dd104db30bb

Libraries/Renderer/ReactFabric-dev.js

@@ -3622,6 +3622,11 @@ var ReactNativeComponent = (function(_React$Component) {
   /**
    * Removes focus. This is the opposite of `focus()`.
    */
+
+  /**
+   * Due to bugs in Flow's handling of React.createClass, some fields already
+   * declared in the base class need to be redeclared below.
+   */
   ReactNativeComponent.prototype.blur = function blur() {
     TextInputState.blurTextInput(findNumericNodeHandleFiber(this));
   };
@@ -8327,11 +8332,11 @@ var rendererSigil = void 0;
 function pushProvider(providerFiber) {
   var context = providerFiber.type.context;
   index$1 += 1;
-  changedBitsStack[index$1] = context.changedBits;
-  currentValueStack[index$1] = context.currentValue;
+  changedBitsStack[index$1] = context._changedBits;
+  currentValueStack[index$1] = context._currentValue;
   stack[index$1] = providerFiber;
-  context.currentValue = providerFiber.pendingProps.value;
-  context.changedBits = providerFiber.stateNode;
+  context._currentValue = providerFiber.pendingProps.value;
+  context._changedBits = providerFiber.stateNode;
 
   {
     warning(
@@ -8358,16 +8363,16 @@ function popProvider(providerFiber) {
   stack[index$1] = null;
   index$1 -= 1;
   var context = providerFiber.type.context;
-  context.currentValue = currentValue;
-  context.changedBits = changedBits;
+  context._currentValue = currentValue;
+  context._changedBits = changedBits;
 }
 
 function resetProviderStack() {
   for (var i = index$1; i > -1; i--) {
     var providerFiber = stack[i];
     var context = providerFiber.type.context;
-    context.currentValue = context.defaultValue;
-    context.changedBits = 0;
+    context._currentValue = context._defaultValue;
+    context._changedBits = 0;
     changedBitsStack[i] = null;
     currentValueStack[i] = null;
     stack[i] = null;
@@ -9149,48 +9154,70 @@ var ReactFiberBeginWork = function(
       pushProvider(workInProgress);
       return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
-    workInProgress.memoizedProps = newProps;
 
     var newValue = newProps.value;
+    workInProgress.memoizedProps = newProps;
 
     var changedBits = void 0;
     if (oldProps === null) {
       // Initial render
       changedBits = MAX_SIGNED_31_BIT_INT;
     } else {
-      var oldValue = oldProps.value;
-      // Use Object.is to compare the new context value to the old value.
-      // Inlined Object.is polyfill.
-      // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
-      if (
-        (oldValue === newValue &&
-          (oldValue !== 0 || 1 / oldValue === 1 / newValue)) ||
-        (oldValue !== oldValue && newValue !== newValue) // eslint-disable-line no-self-compare
-      ) {
-        // No change.
+      if (oldProps.value === newProps.value) {
+        // No change. Bailout early if children are the same.
+        if (oldProps.children === newProps.children) {
+          workInProgress.stateNode = 0;
+          pushProvider(workInProgress);
+          return bailoutOnAlreadyFinishedWork(current, workInProgress);
+        }
         changedBits = 0;
       } else {
-        changedBits =
-          typeof context.calculateChangedBits === "function"
-            ? context.calculateChangedBits(oldValue, newValue)
-            : MAX_SIGNED_31_BIT_INT;
-        {
-          warning(
-            (changedBits & MAX_SIGNED_31_BIT_INT) === changedBits,
-            "calculateChangedBits: Expected the return value to be a " +
-              "31-bit integer. Instead received: %s",
-            changedBits
-          );
-        }
-        changedBits |= 0;
+        var oldValue = oldProps.value;
+        // Use Object.is to compare the new context value to the old value.
+        // Inlined Object.is polyfill.
+        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
+        if (
+          (oldValue === newValue &&
+            (oldValue !== 0 || 1 / oldValue === 1 / newValue)) ||
+          (oldValue !== oldValue && newValue !== newValue) // eslint-disable-line no-self-compare
+        ) {
+          // No change. Bailout early if children are the same.
+          if (oldProps.children === newProps.children) {
+            workInProgress.stateNode = 0;
+            pushProvider(workInProgress);
+            return bailoutOnAlreadyFinishedWork(current, workInProgress);
+          }
+          changedBits = 0;
+        } else {
+          changedBits =
+            typeof context._calculateChangedBits === "function"
+              ? context._calculateChangedBits(oldValue, newValue)
+              : MAX_SIGNED_31_BIT_INT;
+          {
+            warning(
+              (changedBits & MAX_SIGNED_31_BIT_INT) === changedBits,
+              "calculateChangedBits: Expected the return value to be a " +
+                "31-bit integer. Instead received: %s",
+              changedBits
+            );
+          }
+          changedBits |= 0;
 
-        if (changedBits !== 0) {
-          propagateContextChange(
-            workInProgress,
-            context,
-            changedBits,
-            renderExpirationTime
-          );
+          if (changedBits === 0) {
+            // No change. Bailout early if children are the same.
+            if (oldProps.children === newProps.children) {
+              workInProgress.stateNode = 0;
+              pushProvider(workInProgress);
+              return bailoutOnAlreadyFinishedWork(current, workInProgress);
+            }
+          } else {
+            propagateContextChange(
+              workInProgress,
+              context,
+              changedBits,
+              renderExpirationTime
+            );
+          }
         }
       }
     }
@@ -9198,9 +9225,6 @@ var ReactFiberBeginWork = function(
     workInProgress.stateNode = changedBits;
     pushProvider(workInProgress);
 
-    if (oldProps !== null && oldProps.children === newProps.children) {
-      return bailoutOnAlreadyFinishedWork(current, workInProgress);
-    }
     var newChildren = newProps.children;
     reconcileChildren(current, workInProgress, newChildren);
     return workInProgress.child;
@@ -9213,11 +9237,28 @@ var ReactFiberBeginWork = function(
   ) {
     var context = workInProgress.type;
     var newProps = workInProgress.pendingProps;
+    var oldProps = workInProgress.memoizedProps;
 
-    var newValue = context.currentValue;
-    var changedBits = context.changedBits;
+    var newValue = context._currentValue;
+    var changedBits = context._changedBits;
 
-    if (changedBits !== 0) {
+    if (hasContextChanged()) {
+      // Normally we can bail out on props equality but if context has changed
+      // we don't do the bailout and we have to reuse existing props instead.
+    } else if (changedBits === 0 && oldProps === newProps) {
+      return bailoutOnAlreadyFinishedWork(current, workInProgress);
+    }
+    workInProgress.memoizedProps = newProps;
+
+    var observedBits = newProps.unstable_observedBits;
+    if (observedBits === undefined || observedBits === null) {
+      // Subscribe to all changes by default
+      observedBits = MAX_SIGNED_31_BIT_INT;
+    }
+    // Store the observedBits on the fiber's stateNode for quick access.
+    workInProgress.stateNode = observedBits;
+
+    if ((changedBits & observedBits) !== 0) {
       // Context change propagation stops at matching consumers, for time-
       // slicing. Continue the propagation here.
       propagateContextChange(
@@ -9226,24 +9267,20 @@ var ReactFiberBeginWork = function(
         changedBits,
         renderExpirationTime
       );
+    } else if (oldProps !== null && oldProps.children === newProps.children) {
+      // No change. Bailout early if children are the same.
+      return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
 
-    // Store the observedBits on the fiber's stateNode for quick access.
-    var observedBits = newProps.observedBits;
-    if (observedBits === undefined || observedBits === null) {
-      // Subscribe to all changes by default
-      observedBits = MAX_SIGNED_31_BIT_INT;
-    }
-    workInProgress.stateNode = observedBits;
-
     var render = newProps.children;
 
-    if (typeof render !== "function") {
-      invariant(
-        false,
-        "A context consumer was rendered with multiple children, or a child that isn't a function. " +
-          "A context consumer expects a single child that is a function. " +
-          "If you did pass a function, make sure there is no trailing or leading whitespace around it."
+    {
+      warning(
+        typeof render === "function",
+        "A context consumer was rendered with multiple children, or a child " +
+          "that isn't a function. A context consumer expects a single child " +
+          "that is a function. If you did pass a function, make sure there " +
+          "is no trailing or leading whitespace around it."
       );
     }
 

Libraries/Renderer/ReactFabric-prod.js

@@ -3122,11 +3122,11 @@ var reconcileChildFibers = ChildReconciler(!0),
 function pushProvider(providerFiber) {
   var context = providerFiber.type.context;
   index$1 += 1;
-  changedBitsStack[index$1] = context.changedBits;
-  currentValueStack[index$1] = context.currentValue;
+  changedBitsStack[index$1] = context._changedBits;
+  currentValueStack[index$1] = context._currentValue;
   stack[index$1] = providerFiber;
-  context.currentValue = providerFiber.pendingProps.value;
-  context.changedBits = providerFiber.stateNode;
+  context._currentValue = providerFiber.pendingProps.value;
+  context._changedBits = providerFiber.stateNode;
 }
 function popProvider(providerFiber) {
   var changedBits = changedBitsStack[index$1],
@@ -3136,8 +3136,8 @@ function popProvider(providerFiber) {
   stack[index$1] = null;
   --index$1;
   providerFiber = providerFiber.type.context;
-  providerFiber.currentValue = currentValue;
-  providerFiber.changedBits = changedBits;
+  providerFiber._currentValue = currentValue;
+  providerFiber._changedBits = changedBits;
 }
 function ReactFiberBeginWork(
   config,
@@ -3289,6 +3289,72 @@ function ReactFiberBeginWork(
       fiber = nextFiber;
     }
   }
+  function updateContextProvider(
+    current,
+    workInProgress,
+    renderExpirationTime
+  ) {
+    var context = workInProgress.type.context,
+      newProps = workInProgress.pendingProps,
+      oldProps = workInProgress.memoizedProps;
+    if (!didPerformWorkStackCursor.current && oldProps === newProps)
+      return (
+        (workInProgress.stateNode = 0),
+        pushProvider(workInProgress),
+        bailoutOnAlreadyFinishedWork(current, workInProgress)
+      );
+    var newValue = newProps.value;
+    workInProgress.memoizedProps = newProps;
+    if (null === oldProps) newValue = 1073741823;
+    else if (oldProps.value === newProps.value) {
+      if (oldProps.children === newProps.children)
+        return (
+          (workInProgress.stateNode = 0),
+          pushProvider(workInProgress),
+          bailoutOnAlreadyFinishedWork(current, workInProgress)
+        );
+      newValue = 0;
+    } else {
+      var oldValue = oldProps.value;
+      if (
+        (oldValue === newValue &&
+          (0 !== oldValue || 1 / oldValue === 1 / newValue)) ||
+        (oldValue !== oldValue && newValue !== newValue)
+      ) {
+        if (oldProps.children === newProps.children)
+          return (
+            (workInProgress.stateNode = 0),
+            pushProvider(workInProgress),
+            bailoutOnAlreadyFinishedWork(current, workInProgress)
+          );
+        newValue = 0;
+      } else if (
+        ((newValue =
+          "function" === typeof context._calculateChangedBits
+            ? context._calculateChangedBits(oldValue, newValue)
+            : 1073741823),
+        (newValue |= 0),
+        0 === newValue)
+      ) {
+        if (oldProps.children === newProps.children)
+          return (
+            (workInProgress.stateNode = 0),
+            pushProvider(workInProgress),
+            bailoutOnAlreadyFinishedWork(current, workInProgress)
+          );
+      } else
+        propagateContextChange(
+          workInProgress,
+          context,
+          newValue,
+          renderExpirationTime
+        );
+    }
+    workInProgress.stateNode = newValue;
+    pushProvider(workInProgress);
+    reconcileChildren(current, workInProgress, newProps.children);
+    return workInProgress.child;
+  }
   function bailoutOnAlreadyFinishedWork(current, workInProgress) {
     invariant(
       null === current || workInProgress.child === current.child,
@@ -3641,71 +3707,50 @@ function ReactFiberBeginWork(
             current
           );
         case 13:
-          props = workInProgress.type.context;
-          fn = workInProgress.pendingProps;
-          unmaskedContext = workInProgress.memoizedProps;
-          if (didPerformWorkStackCursor.current || unmaskedContext !== fn) {
-            workInProgress.memoizedProps = fn;
-            updateQueue = fn.value;
-            if (null === unmaskedContext) updateQueue = 1073741823;
-            else {
-              var oldValue = unmaskedContext.value;
-              (oldValue === updateQueue &&
-                (0 !== oldValue || 1 / oldValue === 1 / updateQueue)) ||
-              (oldValue !== oldValue && updateQueue !== updateQueue)
-                ? (updateQueue = 0)
-                : ((updateQueue =
-                    "function" === typeof props.calculateChangedBits
-                      ? props.calculateChangedBits(oldValue, updateQueue)
-                      : 1073741823),
-                  (updateQueue |= 0),
-                  0 !== updateQueue &&
-                    propagateContextChange(
-                      workInProgress,
-                      props,
-                      updateQueue,
-                      renderExpirationTime
-                    ));
-            }
-            workInProgress.stateNode = updateQueue;
-            pushProvider(workInProgress);
-            null !== unmaskedContext && unmaskedContext.children === fn.children
-              ? (current = bailoutOnAlreadyFinishedWork(
-                  current,
-                  workInProgress
-                ))
-              : (reconcileChildren(current, workInProgress, fn.children),
-                (current = workInProgress.child));
-          } else
-            (workInProgress.stateNode = 0),
-              pushProvider(workInProgress),
-              (current = bailoutOnAlreadyFinishedWork(current, workInProgress));
-          return current;
+          return updateContextProvider(
+            current,
+            workInProgress,
+            renderExpirationTime
+          );
         case 12:
-          unmaskedContext = workInProgress.type;
-          fn = workInProgress.pendingProps;
-          props = unmaskedContext.currentValue;
-          updateQueue = unmaskedContext.changedBits;
-          0 !== updateQueue &&
-            propagateContextChange(
-              workInProgress,
-              unmaskedContext,
-              updateQueue,
-              renderExpirationTime
-            );
-          renderExpirationTime = fn.observedBits;
-          if (void 0 === renderExpirationTime || null === renderExpirationTime)
-            renderExpirationTime = 1073741823;
-          workInProgress.stateNode = renderExpirationTime;
-          renderExpirationTime = fn.children;
-          "function" !== typeof renderExpirationTime &&
-            invariant(
-              !1,
-              "A context consumer was rendered with multiple children, or a child that isn't a function. A context consumer expects a single child that is a function. If you did pass a function, make sure there is no trailing or leading whitespace around it."
-            );
-          renderExpirationTime = renderExpirationTime(props);
-          reconcileChildren(current, workInProgress, renderExpirationTime);
-          return workInProgress.child;
+          a: {
+            fn = workInProgress.type;
+            unmaskedContext = workInProgress.pendingProps;
+            updateQueue = workInProgress.memoizedProps;
+            props = fn._currentValue;
+            var changedBits = fn._changedBits;
+            if (
+              didPerformWorkStackCursor.current ||
+              0 !== changedBits ||
+              updateQueue !== unmaskedContext
+            ) {
+              workInProgress.memoizedProps = unmaskedContext;
+              var observedBits = unmaskedContext.unstable_observedBits;
+              if (void 0 === observedBits || null === observedBits)
+                observedBits = 1073741823;
+              workInProgress.stateNode = observedBits;
+              if (0 !== (changedBits & observedBits))
+                propagateContextChange(
+                  workInProgress,
+                  fn,
+                  changedBits,
+                  renderExpirationTime
+                );
+              else if (
+                null !== updateQueue &&
+                updateQueue.children === unmaskedContext.children
+              ) {
+                current = bailoutOnAlreadyFinishedWork(current, workInProgress);
+                break a;
+              }
+              renderExpirationTime = unmaskedContext.children;
+              renderExpirationTime = renderExpirationTime(props);
+              reconcileChildren(current, workInProgress, renderExpirationTime);
+              current = workInProgress.child;
+            } else
+              current = bailoutOnAlreadyFinishedWork(current, workInProgress);
+          }
+          return current;
         default:
           invariant(
             !1,
@@ -4581,8 +4626,8 @@ function ReactFiberScheduler(config) {
     resetHostContainer();
     for (var i = index$1; -1 < i; i--) {
       var context = stack[i].type.context;
-      context.currentValue = context.defaultValue;
-      context.changedBits = 0;
+      context._currentValue = context._defaultValue;
+      context._changedBits = 0;
       changedBitsStack[i] = null;
       currentValueStack[i] = null;
       stack[i] = null;

Libraries/Renderer/ReactNativeRenderer-dev.js

@@ -3968,6 +3968,11 @@ var ReactNativeComponent = (function(_React$Component) {
   /**
    * Removes focus. This is the opposite of `focus()`.
    */
+
+  /**
+   * Due to bugs in Flow's handling of React.createClass, some fields already
+   * declared in the base class need to be redeclared below.
+   */
   ReactNativeComponent.prototype.blur = function blur() {
     TextInputState.blurTextInput(findNumericNodeHandleFiber(this));
   };
@@ -8585,11 +8590,11 @@ var rendererSigil = void 0;
 function pushProvider(providerFiber) {
   var context = providerFiber.type.context;
   index$1 += 1;
-  changedBitsStack[index$1] = context.changedBits;
-  currentValueStack[index$1] = context.currentValue;
+  changedBitsStack[index$1] = context._changedBits;
+  currentValueStack[index$1] = context._currentValue;
   stack[index$1] = providerFiber;
-  context.currentValue = providerFiber.pendingProps.value;
-  context.changedBits = providerFiber.stateNode;
+  context._currentValue = providerFiber.pendingProps.value;
+  context._changedBits = providerFiber.stateNode;
 
   {
     warning(
@@ -8616,16 +8621,16 @@ function popProvider(providerFiber) {
   stack[index$1] = null;
   index$1 -= 1;
   var context = providerFiber.type.context;
-  context.currentValue = currentValue;
-  context.changedBits = changedBits;
+  context._currentValue = currentValue;
+  context._changedBits = changedBits;
 }
 
 function resetProviderStack() {
   for (var i = index$1; i > -1; i--) {
     var providerFiber = stack[i];
     var context = providerFiber.type.context;
-    context.currentValue = context.defaultValue;
-    context.changedBits = 0;
+    context._currentValue = context._defaultValue;
+    context._changedBits = 0;
     changedBitsStack[i] = null;
     currentValueStack[i] = null;
     stack[i] = null;
@@ -9407,48 +9412,70 @@ var ReactFiberBeginWork = function(
       pushProvider(workInProgress);
       return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
-    workInProgress.memoizedProps = newProps;
 
     var newValue = newProps.value;
+    workInProgress.memoizedProps = newProps;
 
     var changedBits = void 0;
     if (oldProps === null) {
       // Initial render
       changedBits = MAX_SIGNED_31_BIT_INT;
     } else {
-      var oldValue = oldProps.value;
-      // Use Object.is to compare the new context value to the old value.
-      // Inlined Object.is polyfill.
-      // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
-      if (
-        (oldValue === newValue &&
-          (oldValue !== 0 || 1 / oldValue === 1 / newValue)) ||
-        (oldValue !== oldValue && newValue !== newValue) // eslint-disable-line no-self-compare
-      ) {
-        // No change.
+      if (oldProps.value === newProps.value) {
+        // No change. Bailout early if children are the same.
+        if (oldProps.children === newProps.children) {
+          workInProgress.stateNode = 0;
+          pushProvider(workInProgress);
+          return bailoutOnAlreadyFinishedWork(current, workInProgress);
+        }
         changedBits = 0;
       } else {
-        changedBits =
-          typeof context.calculateChangedBits === "function"
-            ? context.calculateChangedBits(oldValue, newValue)
-            : MAX_SIGNED_31_BIT_INT;
-        {
-          warning(
-            (changedBits & MAX_SIGNED_31_BIT_INT) === changedBits,
-            "calculateChangedBits: Expected the return value to be a " +
-              "31-bit integer. Instead received: %s",
-            changedBits
-          );
-        }
-        changedBits |= 0;
+        var oldValue = oldProps.value;
+        // Use Object.is to compare the new context value to the old value.
+        // Inlined Object.is polyfill.
+        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/is
+        if (
+          (oldValue === newValue &&
+            (oldValue !== 0 || 1 / oldValue === 1 / newValue)) ||
+          (oldValue !== oldValue && newValue !== newValue) // eslint-disable-line no-self-compare
+        ) {
+          // No change. Bailout early if children are the same.
+          if (oldProps.children === newProps.children) {
+            workInProgress.stateNode = 0;
+            pushProvider(workInProgress);
+            return bailoutOnAlreadyFinishedWork(current, workInProgress);
+          }
+          changedBits = 0;
+        } else {
+          changedBits =
+            typeof context._calculateChangedBits === "function"
+              ? context._calculateChangedBits(oldValue, newValue)
+              : MAX_SIGNED_31_BIT_INT;
+          {
+            warning(
+              (changedBits & MAX_SIGNED_31_BIT_INT) === changedBits,
+              "calculateChangedBits: Expected the return value to be a " +
+                "31-bit integer. Instead received: %s",
+              changedBits
+            );
+          }
+          changedBits |= 0;
 
-        if (changedBits !== 0) {
-          propagateContextChange(
-            workInProgress,
-            context,
-            changedBits,
-            renderExpirationTime
-          );
+          if (changedBits === 0) {
+            // No change. Bailout early if children are the same.
+            if (oldProps.children === newProps.children) {
+              workInProgress.stateNode = 0;
+              pushProvider(workInProgress);
+              return bailoutOnAlreadyFinishedWork(current, workInProgress);
+            }
+          } else {
+            propagateContextChange(
+              workInProgress,
+              context,
+              changedBits,
+              renderExpirationTime
+            );
+          }
         }
       }
     }
@@ -9456,9 +9483,6 @@ var ReactFiberBeginWork = function(
     workInProgress.stateNode = changedBits;
     pushProvider(workInProgress);
 
-    if (oldProps !== null && oldProps.children === newProps.children) {
-      return bailoutOnAlreadyFinishedWork(current, workInProgress);
-    }
     var newChildren = newProps.children;
     reconcileChildren(current, workInProgress, newChildren);
     return workInProgress.child;
@@ -9471,11 +9495,28 @@ var ReactFiberBeginWork = function(
   ) {
     var context = workInProgress.type;
     var newProps = workInProgress.pendingProps;
+    var oldProps = workInProgress.memoizedProps;
 
-    var newValue = context.currentValue;
-    var changedBits = context.changedBits;
+    var newValue = context._currentValue;
+    var changedBits = context._changedBits;
 
-    if (changedBits !== 0) {
+    if (hasContextChanged()) {
+      // Normally we can bail out on props equality but if context has changed
+      // we don't do the bailout and we have to reuse existing props instead.
+    } else if (changedBits === 0 && oldProps === newProps) {
+      return bailoutOnAlreadyFinishedWork(current, workInProgress);
+    }
+    workInProgress.memoizedProps = newProps;
+
+    var observedBits = newProps.unstable_observedBits;
+    if (observedBits === undefined || observedBits === null) {
+      // Subscribe to all changes by default
+      observedBits = MAX_SIGNED_31_BIT_INT;
+    }
+    // Store the observedBits on the fiber's stateNode for quick access.
+    workInProgress.stateNode = observedBits;
+
+    if ((changedBits & observedBits) !== 0) {
       // Context change propagation stops at matching consumers, for time-
       // slicing. Continue the propagation here.
       propagateContextChange(
@@ -9484,24 +9525,20 @@ var ReactFiberBeginWork = function(
         changedBits,
         renderExpirationTime
       );
+    } else if (oldProps !== null && oldProps.children === newProps.children) {
+      // No change. Bailout early if children are the same.
+      return bailoutOnAlreadyFinishedWork(current, workInProgress);
     }
 
-    // Store the observedBits on the fiber's stateNode for quick access.
-    var observedBits = newProps.observedBits;
-    if (observedBits === undefined || observedBits === null) {
-      // Subscribe to all changes by default
-      observedBits = MAX_SIGNED_31_BIT_INT;
-    }
-    workInProgress.stateNode = observedBits;
-
     var render = newProps.children;
 
-    if (typeof render !== "function") {
-      invariant(
-        false,
-        "A context consumer was rendered with multiple children, or a child that isn't a function. " +
-          "A context consumer expects a single child that is a function. " +
-          "If you did pass a function, make sure there is no trailing or leading whitespace around it."
+    {
+      warning(
+        typeof render === "function",
+        "A context consumer was rendered with multiple children, or a child " +
+          "that isn't a function. A context consumer expects a single child " +
+          "that is a function. If you did pass a function, make sure there " +
+          "is no trailing or leading whitespace around it."
       );
     }
 

Libraries/Renderer/ReactNativeRenderer-prod.js

@@ -3376,11 +3376,11 @@ var reconcileChildFibers = ChildReconciler(!0),
 function pushProvider(providerFiber) {
   var context = providerFiber.type.context;
   index$1 += 1;
-  changedBitsStack[index$1] = context.changedBits;
-  currentValueStack[index$1] = context.currentValue;
+  changedBitsStack[index$1] = context._changedBits;
+  currentValueStack[index$1] = context._currentValue;
   stack[index$1] = providerFiber;
-  context.currentValue = providerFiber.pendingProps.value;
-  context.changedBits = providerFiber.stateNode;
+  context._currentValue = providerFiber.pendingProps.value;
+  context._changedBits = providerFiber.stateNode;
 }
 function popProvider(providerFiber) {
   var changedBits = changedBitsStack[index$1],
@@ -3390,8 +3390,8 @@ function popProvider(providerFiber) {
   stack[index$1] = null;
   --index$1;
   providerFiber = providerFiber.type.context;
-  providerFiber.currentValue = currentValue;
-  providerFiber.changedBits = changedBits;
+  providerFiber._currentValue = currentValue;
+  providerFiber._changedBits = changedBits;
 }
 function ReactFiberBeginWork(
   config,
@@ -3552,6 +3552,72 @@ function ReactFiberBeginWork(
       fiber = nextFiber;
     }
   }
+  function updateContextProvider(
+    current,
+    workInProgress,
+    renderExpirationTime
+  ) {
+    var context = workInProgress.type.context,
+      newProps = workInProgress.pendingProps,
+      oldProps = workInProgress.memoizedProps;
+    if (!didPerformWorkStackCursor.current && oldProps === newProps)
+      return (
+        (workInProgress.stateNode = 0),
+        pushProvider(workInProgress),
+        bailoutOnAlreadyFinishedWork(current, workInProgress)
+      );
+    var newValue = newProps.value;
+    workInProgress.memoizedProps = newProps;
+    if (null === oldProps) newValue = 1073741823;
+    else if (oldProps.value === newProps.value) {
+      if (oldProps.children === newProps.children)
+        return (
+          (workInProgress.stateNode = 0),
+          pushProvider(workInProgress),
+          bailoutOnAlreadyFinishedWork(current, workInProgress)
+        );
+      newValue = 0;
+    } else {
+      var oldValue = oldProps.value;
+      if (
+        (oldValue === newValue &&
+          (0 !== oldValue || 1 / oldValue === 1 / newValue)) ||
+        (oldValue !== oldValue && newValue !== newValue)
+      ) {
+        if (oldProps.children === newProps.children)
+          return (
+            (workInProgress.stateNode = 0),
+            pushProvider(workInProgress),
+            bailoutOnAlreadyFinishedWork(current, workInProgress)
+          );
+        newValue = 0;
+      } else if (
+        ((newValue =
+          "function" === typeof context._calculateChangedBits
+            ? context._calculateChangedBits(oldValue, newValue)
+            : 1073741823),
+        (newValue |= 0),
+        0 === newValue)
+      ) {
+        if (oldProps.children === newProps.children)
+          return (
+            (workInProgress.stateNode = 0),
+            pushProvider(workInProgress),
+            bailoutOnAlreadyFinishedWork(current, workInProgress)
+          );
+      } else
+        propagateContextChange(
+          workInProgress,
+          context,
+          newValue,
+          renderExpirationTime
+        );
+    }
+    workInProgress.stateNode = newValue;
+    pushProvider(workInProgress);
+    reconcileChildren(current, workInProgress, newProps.children);
+    return workInProgress.child;
+  }
   function bailoutOnAlreadyFinishedWork(current, workInProgress) {
     invariant(
       null === current || workInProgress.child === current.child,
@@ -3904,71 +3970,50 @@ function ReactFiberBeginWork(
             current
           );
         case 13:
-          props = workInProgress.type.context;
-          fn = workInProgress.pendingProps;
-          unmaskedContext = workInProgress.memoizedProps;
-          if (didPerformWorkStackCursor.current || unmaskedContext !== fn) {
-            workInProgress.memoizedProps = fn;
-            updateQueue = fn.value;
-            if (null === unmaskedContext) updateQueue = 1073741823;
-            else {
-              var oldValue = unmaskedContext.value;
-              (oldValue === updateQueue &&
-                (0 !== oldValue || 1 / oldValue === 1 / updateQueue)) ||
-              (oldValue !== oldValue && updateQueue !== updateQueue)
-                ? (updateQueue = 0)
-                : ((updateQueue =
-                    "function" === typeof props.calculateChangedBits
-                      ? props.calculateChangedBits(oldValue, updateQueue)
-                      : 1073741823),
-                  (updateQueue |= 0),
-                  0 !== updateQueue &&
-                    propagateContextChange(
-                      workInProgress,
-                      props,
-                      updateQueue,
-                      renderExpirationTime
-                    ));
-            }
-            workInProgress.stateNode = updateQueue;
-            pushProvider(workInProgress);
-            null !== unmaskedContext && unmaskedContext.children === fn.children
-              ? (current = bailoutOnAlreadyFinishedWork(
-                  current,
-                  workInProgress
-                ))
-              : (reconcileChildren(current, workInProgress, fn.children),
-                (current = workInProgress.child));
-          } else
-            (workInProgress.stateNode = 0),
-              pushProvider(workInProgress),
-              (current = bailoutOnAlreadyFinishedWork(current, workInProgress));
-          return current;
+          return updateContextProvider(
+            current,
+            workInProgress,
+            renderExpirationTime
+          );
         case 12:
-          unmaskedContext = workInProgress.type;
-          fn = workInProgress.pendingProps;
-          props = unmaskedContext.currentValue;
-          updateQueue = unmaskedContext.changedBits;
-          0 !== updateQueue &&
-            propagateContextChange(
-              workInProgress,
-              unmaskedContext,
-              updateQueue,
-              renderExpirationTime
-            );
-          renderExpirationTime = fn.observedBits;
-          if (void 0 === renderExpirationTime || null === renderExpirationTime)
-            renderExpirationTime = 1073741823;
-          workInProgress.stateNode = renderExpirationTime;
-          renderExpirationTime = fn.children;
-          "function" !== typeof renderExpirationTime &&
-            invariant(
-              !1,
-              "A context consumer was rendered with multiple children, or a child that isn't a function. A context consumer expects a single child that is a function. If you did pass a function, make sure there is no trailing or leading whitespace around it."
-            );
-          renderExpirationTime = renderExpirationTime(props);
-          reconcileChildren(current, workInProgress, renderExpirationTime);
-          return workInProgress.child;
+          a: {
+            fn = workInProgress.type;
+            unmaskedContext = workInProgress.pendingProps;
+            updateQueue = workInProgress.memoizedProps;
+            props = fn._currentValue;
+            var changedBits = fn._changedBits;
+            if (
+              didPerformWorkStackCursor.current ||
+              0 !== changedBits ||
+              updateQueue !== unmaskedContext
+            ) {
+              workInProgress.memoizedProps = unmaskedContext;
+              var observedBits = unmaskedContext.unstable_observedBits;
+              if (void 0 === observedBits || null === observedBits)
+                observedBits = 1073741823;
+              workInProgress.stateNode = observedBits;
+              if (0 !== (changedBits & observedBits))
+                propagateContextChange(
+                  workInProgress,
+                  fn,
+                  changedBits,
+                  renderExpirationTime
+                );
+              else if (
+                null !== updateQueue &&
+                updateQueue.children === unmaskedContext.children
+              ) {
+                current = bailoutOnAlreadyFinishedWork(current, workInProgress);
+                break a;
+              }
+              renderExpirationTime = unmaskedContext.children;
+              renderExpirationTime = renderExpirationTime(props);
+              reconcileChildren(current, workInProgress, renderExpirationTime);
+              current = workInProgress.child;
+            } else
+              current = bailoutOnAlreadyFinishedWork(current, workInProgress);
+          }
+          return current;
         default:
           invariant(
             !1,
@@ -4977,8 +5022,8 @@ function ReactFiberScheduler(config) {
     resetHostContainer();
     for (var i = index$1; -1 < i; i--) {
       var context = stack[i].type.context;
-      context.currentValue = context.defaultValue;
-      context.changedBits = 0;
+      context._currentValue = context._defaultValue;
+      context._changedBits = 0;
       changedBitsStack[i] = null;
       currentValueStack[i] = null;
       stack[i] = null;

Libraries/Renderer/shims/ReactFabric.js

@@ -9,8 +9,6 @@
  */
 'use strict';
 
-const BatchedBridge = require('BatchedBridge');
-
 // TODO @sema: Adjust types
 import type {ReactNativeType} from 'ReactNativeTypes';
 
@@ -22,6 +20,4 @@ if (__DEV__) {
   ReactFabric = require('ReactFabric-prod');
 }
 
-BatchedBridge.registerCallableModule('ReactFabric', ReactFabric);
-
 module.exports = (ReactFabric: ReactNativeType);

Libraries/Renderer/shims/ReactNativeTypes.js

@@ -86,27 +86,12 @@ type SecretInternalsType = {
   // And how much information to fill in for the above types.
 };
 
-declare class ReactNativeComponent<Props, State = void>
-  extends React$Component<Props, State> {
-
-  blur(): void,
-  focus(): void,
-  measure(callback: MeasureOnSuccessCallback): void,
-  measureInWindow(callback: MeasureInWindowOnSuccessCallback): void,
-  measureLayout(
-    relativeToNativeNode: number,
-    onSuccess: MeasureLayoutOnSuccessCallback,
-    onFail: () => void,
-  ): void,
-  setNativeProps(nativeProps: Object): void,
-}
-
 /**
  * Flat ReactNative renderer bundles are too big for Flow to parse efficiently.
  * Provide minimal Flow typing for the high-level RN API and call it a day.
  */
 export type ReactNativeType = {
-  NativeComponent: typeof ReactNativeComponent,
+  NativeComponent: any,
   findNodeHandle(componentOrHandle: any): ?number,
   render(
     element: React$Element<any>,

Libraries/Renderer/shims/ReactTypes.js

@@ -80,10 +80,12 @@ export type ReactContext<T> = {
   $$typeof: Symbol | number,
   Consumer: ReactContext<T>,
   Provider: ReactProviderType<T>,
-  calculateChangedBits: ((a: T, b: T) => number) | null,
-  defaultValue: T,
-  currentValue: T,
-  changedBits: number,
+
+  _calculateChangedBits: ((a: T, b: T) => number) | null,
+  _defaultValue: T,
+
+  _currentValue: T,
+  _changedBits: number,
 
   // DEV only
   _currentRenderer?: Object | null,