destroy react instance on background critical memory pressure

Reviewed By: astreet

Differential Revision: D2989125

fb-gh-sync-id: 0e441409d6b0ea7d5ff6a037730cc1c36818a2da
shipit-source-id: 0e441409d6b0ea7d5ff6a037730cc1c36818a2da

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManager.java

@@ -62,6 +62,8 @@ public abstract class ReactInstanceManager {
 
   public abstract DevSupportManager getDevSupportManager();
 
+  public abstract MemoryPressureRouter getMemoryPressureRouter();
+
   /**
    * Trigger react context initialization asynchronously in a background async task. This enables
    * applications to pre-load the application JS, and execute global code before
@@ -159,6 +161,8 @@ public abstract class ReactInstanceManager {
   @VisibleForTesting
   public abstract @Nullable ReactContext getCurrentReactContext();
 
+  public abstract LifecycleState getLifecycleState();
+
   /**
    * Creates a builder that is capable of creating an instance of {@link ReactInstanceManagerImpl}.
    */

ReactAndroid/src/main/java/com/facebook/react/ReactInstanceManagerImpl.java

@@ -308,6 +308,11 @@ import static com.facebook.react.bridge.ReactMarkerConstants.RUN_JS_BUNDLE_START
     return mDevSupportManager;
   }
 
+  @Override
+  public MemoryPressureRouter getMemoryPressureRouter() {
+    return mMemoryPressureRouter;
+  }
+
   private static void initializeSoLoaderIfNecessary(Context applicationContext) {
     // Call SoLoader.initialize here, this is required for apps that does not use exopackage and
     // does not use SoLoader for loading other native code except from the one used by React Native
@@ -582,6 +587,10 @@ import static com.facebook.react.bridge.ReactMarkerConstants.RUN_JS_BUNDLE_START
     mLifecycleState = LifecycleState.BEFORE_CREATE;
   }
 
+  public LifecycleState getLifecycleState() {
+    return mLifecycleState;
+  }
+
   @Override
   public void onActivityResult(int requestCode, int resultCode, Intent data) {
     if (mCurrentReactContext != null) {