Make Page Visibility API work when the browser window is visible or not

content/test/test_render_view_host.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_TEST_TEST_RENDER_VIEW_HOST_H_
 #define CONTENT_TEST_TEST_RENDER_VIEW_HOST_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 51 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;
   ui::TextInputClient* GetTextInputClient() override;
   bool HasFocus() const override;
   bool IsSurfaceAvailableForCopy() const override;
   void Show() override;
   void Hide() override;
+  void Hide(bool content_visible) override {}
   bool IsShowing() override;
   void WasUnOccluded() override;
   void WasOccluded() override;
   gfx::Rect GetViewBounds() const override;
 #if defined(OS_MACOSX)
   void SetActive(bool active) override;
   void SetWindowVisibility(bool visible) override {}
   void WindowFrameChanged() override {}
   void ShowDefinitionForSelection() override {}
   bool SupportsSpeech() const override;
@@ skipping 239 matching lines @@
  private:
   typedef scoped_ptr<ui::test::ScopedSetSupportedScaleFactors>
       ScopedSetSupportedScaleFactors;
   ScopedSetSupportedScaleFactors scoped_set_supported_scale_factors_;
   DISALLOW_COPY_AND_ASSIGN(RenderViewHostImplTestHarness);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_TEST_TEST_RENDER_VIEW_HOST_H_