Report jsc memory information to fbsystrace

Reviewed By: jspahrsummers

Differential Revision: D2789593

fb-gh-sync-id: e31d5f174b9cf896ce3be6431d81264d1d240fdb

Libraries/Utilities/MessageQueue.js

@@ -147,6 +147,7 @@ class MessageQueue {
       this._queue = [[],[],[]];
       this._lastFlush = now;
     }
+    Systrace.counterEvent('pending_js_to_native_queue', this._queue[0].length);
     if (__DEV__ && SPY_MODE && isFinite(module)) {
       console.log('JS->N : ' + this._remoteModuleTable[module] + '.' +
         this._remoteMethodTable[module][method] + '(' + JSON.stringify(params) + ')');

Libraries/Utilities/Systrace.js

@@ -92,6 +92,18 @@ var Systrace = {
     }
   },
 
+  /**
+   * counterEvent registers the value to the profileName on the systrace timeline
+  **/
+  counterEvent(profileName?: any, value?: any) {
+    if (_enabled) {
+      profileName = typeof profileName === 'function' ?
+        profileName() : profileName;
+      global.nativeTraceCounter &&
+        global.nativeTraceCounter(TRACE_TAG_REACT_APPS, profileName, value);
+    }
+  },
+
   reactPerfMeasure(objName: string, fnName: string, func: any): any {
     return function (component) {
       if (!_enabled) {