Implement pointer lock across outer/inner WebContents.

content/browser/renderer_host/render_widget_host_delegate.h

Index: content/browser/renderer_host/render_widget_host_delegate.h
diff --git a/content/browser/renderer_host/render_widget_host_delegate.h b/content/browser/renderer_host/render_widget_host_delegate.h
index 8319bc6534d81d61f0055fb7f4d962d27db6c705..0816a6eaddfc5cd4c20513da61b36481195a8fb5 100644
--- a/content/browser/renderer_host/render_widget_host_delegate.h
+++ b/content/browser/renderer_host/render_widget_host_delegate.h
@@ -40,6 +40,7 @@ class RenderWidgetHostImpl;
 class RenderWidgetHostInputEventRouter;
 class RenderViewHostDelegateView;
 class TextInputManager;
+class WebContents;
 struct ScreenInfo;
 struct NativeWebKeyboardEvent;
 
@@ -244,6 +245,10 @@ class CONTENT_EXPORT RenderWidgetHostDelegate {
   // if the eTLD+1 is not known for |render_widget_host|.
   virtual bool AddDomainInfoToRapporSample(rappor::Sample* sample);
 
+  // Return this object cast to a WebContents, if it is one. If the object is
+  // not a WebContents, returns nullptr.
+  virtual WebContents* GetAsWebContents();
+
  protected:
   virtual ~RenderWidgetHostDelegate() {}
 };