Fix bump-scroll on Mac.

remoting/webapp/fullscreen_v1.js

Index: remoting/webapp/fullscreen_v1.js
diff --git a/remoting/webapp/fullscreen_v1.js b/remoting/webapp/fullscreen_v1.js
index 063925b715708a0cb5317be6a56a3715ed55bc3a..5935e3555433988d3c5260063d10f7989b577bb2 100644
--- a/remoting/webapp/fullscreen_v1.js
+++ b/remoting/webapp/fullscreen_v1.js
@@ -79,5 +79,15 @@ remoting.FullscreenAppsV1.prototype.removeListener = function(callback) {
  * @private
  */
 remoting.FullscreenAppsV1.prototype.onFullscreenChanged_ = function() {
-  this.eventSource_.raiseEvent(this.kEventName_, this.isActive());
+  // Querying full-screen immediately after the webkitfullscreenchange
+  // event fires sometimes gives the wrong answer on Mac, perhaps due to
+  // the time taken to animate presentation mode. Since I haven't been able
+  // to isolate the exact repro steps, and we're not planning on using this
+  // API for much longer, this hack will suffice for now.
+  window.setTimeout(
+      /** @this {remoting.FullscreenAppsV1} */
+      function() {
+        this.eventSource_.raiseEvent(this.kEventName_, this.isActive());
+      }.bind(this),
+      500);
 };