pepper: Use the RenderThread's shared context as the parent context.

content/renderer/render_widget_fullscreen_pepper.h

Index: content/renderer/render_widget_fullscreen_pepper.h
diff --git a/content/renderer/render_widget_fullscreen_pepper.h b/content/renderer/render_widget_fullscreen_pepper.h
index a20d53c9baa303831a9e11364cf39213f302f3a1..c7b5422aa78827ff87b7adbbfda9b2fb06b8c6d9 100644
--- a/content/renderer/render_widget_fullscreen_pepper.h
+++ b/content/renderer/render_widget_fullscreen_pepper.h
@@ -9,7 +9,6 @@
 #include "base/memory/weak_ptr.h"
 #include "content/common/gpu/client/webgraphicscontext3d_command_buffer_impl.h"
 #include "content/renderer/mouse_lock_dispatcher.h"
-#include "content/renderer/pepper/pepper_parent_context_provider.h"
 #include "content/renderer/render_widget_fullscreen.h"
 #include "third_party/WebKit/Source/Platform/chromium/public/WebGraphicsContext3D.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/WebWidget.h"
@@ -32,7 +31,6 @@ class WebGraphicsContext3DCommandBufferImpl;
 class RenderWidgetFullscreenPepper :
     public RenderWidgetFullscreen,
     public webkit::ppapi::FullscreenContainer,
-    public PepperParentContextProvider,
     public WebGraphicsContext3DSwapBuffersClient {
  public:
   static RenderWidgetFullscreenPepper* Create(
@@ -111,10 +109,6 @@ class RenderWidgetFullscreenPepper :
   // and notify the browser.
   bool CheckCompositing();
 
-  // Implementation of PepperParentContextProvider.
-  virtual WebGraphicsContext3DCommandBufferImpl*
-      GetParentContextForPlatformContext3D() OVERRIDE;
-
   // URL that is responsible for this widget, passed to ggl::CreateViewContext.
   GURL active_url_;