Implement autoplay gesture override experiment.

Source/core/frame/FrameView.cpp

Index: Source/core/frame/FrameView.cpp
diff --git a/Source/core/frame/FrameView.cpp b/Source/core/frame/FrameView.cpp
index cdfa3a72851e8005b125f67f28d907238286c97d..e660f38d0fa0215f69f4ff341a959db419e7434d 100644
--- a/Source/core/frame/FrameView.cpp
+++ b/Source/core/frame/FrameView.cpp
@@ -2479,6 +2479,9 @@ void FrameView::updateLifecyclePhasesInternal(LifeCycleUpdateOption phases)
             ASSERT(lifecycle().state() == DocumentLifecycle::PaintInvalidationClean
                 || (RuntimeEnabledFeatures::slimmingPaintV2Enabled() && lifecycle().state() == DocumentLifecycle::CompositingForSlimmingPaintV2Clean));
         }
+
+        // Temporary callback for crbug.com/487345,402044
+        view->sendMediaPositionChangeNotifications();

[ojan, 2015/09/01 20:20:11]

Please move this to the end of the AllPhases branch right above here.

Also, add:
TODO(ojan): Make this more general to be used by PositionObserver and rAF
throttling.

[liberato (no reviews please), 2015/09/04 06:49:45]

Done.

     }
 
 #ifndef NDEBUG