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

content/browser/frame_host/render_widget_host_view_child_frame.cc

 // 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.
 
 #include "content/browser/frame_host/render_widget_host_view_child_frame.h"
 
 #include <algorithm>
 #include <utility>
 #include <vector>
 
@@ skipping 533 matching lines @@
 gfx::Point RenderWidgetHostViewChildFrame::TransformPointToCoordSpaceForView(
     const gfx::Point& point,
     RenderWidgetHostViewBase* target_view) {
   if (!frame_connector_ || local_frame_id_.is_null() || target_view == this)
     return point;
 
   return frame_connector_->TransformPointToCoordSpaceForView(
       point, target_view, cc::SurfaceId(frame_sink_id_, local_frame_id_));
 }
 
+bool RenderWidgetHostViewChildFrame::IsRenderWidgetHostViewChildFrame() {
+  return true;
+}
+
 #if defined(OS_MACOSX)
 ui::AcceleratedWidgetMac*
 RenderWidgetHostViewChildFrame::GetAcceleratedWidgetMac() const {
   return nullptr;
 }
 
 void RenderWidgetHostViewChildFrame::SetActive(bool active) {
 }
 
 void RenderWidgetHostViewChildFrame::ShowDefinitionForSelection() {
@@ skipping 165 matching lines @@
 
 bool RenderWidgetHostViewChildFrame::IsChildFrameForTesting() const {
   return true;
 }
 
 cc::SurfaceId RenderWidgetHostViewChildFrame::SurfaceIdForTesting() const {
   return cc::SurfaceId(frame_sink_id_, local_frame_id_);
 };
 
 }  // namespace content