Add occlusion support to WebContentsImpl and RenderWidgetHostView

content/browser/renderer_host/render_widget_host_view_mac.h

 // Copyright (c) 2012 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_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 #include <IOSurface/IOSurfaceAPI.h>
 #include <list>
@@ skipping 227 matching lines @@
   void SetBounds(const gfx::Rect& rect) override;
   gfx::Vector2dF GetLastScrollOffset() const override;
   gfx::NativeView GetNativeView() const override;
   gfx::NativeViewId GetNativeViewId() const override;
   gfx::NativeViewAccessible GetNativeViewAccessible() override;
   bool HasFocus() const override;
   bool IsSurfaceAvailableForCopy() const override;
   void Show() override;
   void Hide() override;
   bool IsShowing() override;
+  void WasUnOccluded() override;
+  void WasOccluded() override;
   gfx::Rect GetViewBounds() const override;
   void SetShowingContextMenu(bool showing) override;
   void SetActive(bool active) override;
   void SetWindowVisibility(bool visible) override;
   void WindowFrameChanged() override;
   void ShowDefinitionForSelection() override;
   bool SupportsSpeech() const override;
   void SpeakSelection() override;
   bool IsSpeaking() const override;
   void StopSpeaking() override;
@@ skipping 292 matching lines @@
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RenderWidgetHostViewMac);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_RENDER_WIDGET_HOST_VIEW_MAC_H_