MouseWheelEventQueue should respect ScrollBegin/End state from RenderWidgetHost.

content/browser/renderer_host/render_widget_host_impl.h

Index: content/browser/renderer_host/render_widget_host_impl.h
diff --git a/content/browser/renderer_host/render_widget_host_impl.h b/content/browser/renderer_host/render_widget_host_impl.h
index c6c682fa6e90c08649c1d8bf22a845ae0c4683ce..eece7d404417c9ebf0595ba945b82bdeaac67529 100644
--- a/content/browser/renderer_host/render_widget_host_impl.h
+++ b/content/browser/renderer_host/render_widget_host_impl.h
@@ -296,12 +296,6 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
   // Notifies the RenderWidgetHost that the View was destroyed.
   void ViewDestroyed();
 
-  // Signals if this host has forwarded a GestureScrollBegin without yet having
-  // forwarded a matching GestureScrollEnd/GestureFlingStart.
-  bool is_in_touchscreen_gesture_scroll() const {
-    return is_in_touchscreen_gesture_scroll_;
-  }
-
 #if defined(OS_MACOSX)
   // Pause for a moment to wait for pending repaint or resize messages sent to
   // the renderer to arrive. If pending resize messages are for an old window
@@ -358,6 +352,10 @@ class CONTENT_EXPORT RenderWidgetHostImpl : public RenderWidgetHost,
       const blink::WebMouseWheelEvent& wheel_event,
       const ui::LatencyInfo& ui_latency);  // Virtual for testing.
 
+  // Signals if this host has forwarded a GestureScrollBegin without yet having
+  // forwarded a matching GestureScrollEnd/GestureFlingStart.
+  bool IsInGestureScroll(blink::WebGestureDevice device) const override;
+
   // Enables/disables touch emulation using mouse event. See TouchEmulator.
   void SetTouchEventEmulationEnabled(
       bool enabled, ui::GestureProviderConfigType config_type);