Clear last MouseMove root view in RWHIER if that view gets destroyed

content/browser/frame_host/render_widget_host_view_child_frame.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 #define CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 122 matching lines @@
   void ProcessGestureEvent(const blink::WebGestureEvent& event,
                            const ui::LatencyInfo& latency) override;
   gfx::Point TransformPointToRootCoordSpace(const gfx::Point& point) override;
   gfx::Point TransformPointToLocalCoordSpace(
       const gfx::Point& point,
       const cc::SurfaceId& original_surface) override;
   gfx::Point TransformPointToCoordSpaceForView(
       const gfx::Point& point,
       RenderWidgetHostViewBase* target_view) override;
 
+  bool IsRenderWidgetHostViewChildFrame() override;
+
 #if defined(OS_MACOSX)
   // RenderWidgetHostView implementation.
   ui::AcceleratedWidgetMac* GetAcceleratedWidgetMac() const override;
   void SetActive(bool active) override;
   void ShowDefinitionForSelection() override;
   bool SupportsSpeech() const override;
   void SpeakSelection() override;
   bool IsSpeaking() const override;
   void StopSpeaking() override;
 #endif  // defined(OS_MACOSX)
@@ skipping 95 matching lines @@
   // The surface client ID of the parent RenderWidgetHostView.  0 if none.
   cc::FrameSinkId parent_frame_sink_id_;
 
   base::WeakPtrFactory<RenderWidgetHostViewChildFrame> weak_factory_;
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewChildFrame);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_FRAME_HOST_RENDER_WIDGET_HOST_VIEW_CHILD_FRAME_H_