Ignore show messages from RemoteFrames when the WebContents is hidden.

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 a72360c42728ceeb3eabb72701806cbb68b1ea6b..4b2295eac8bc154097aa737e8b74725f62d189e8 100644
--- a/content/browser/renderer_host/render_widget_host_delegate.h
+++ b/content/browser/renderer_host/render_widget_host_delegate.h
@@ -194,6 +194,9 @@ class CONTENT_EXPORT RenderWidgetHostDelegate {
   // Returns the TextInputManager tracking text input state.
   virtual TextInputManager* GetTextInputManager();
 
+  // Returns true if this RenderWidgetHost should be hidden.

[kenrb, 2016/07/18 17:11:45]

I don't think this comment is very clear. My interpretation of this method would
be that it asks the delegate if the RenderWidgetHost can be shown, in the event
that something other than the WebContents is attempting to enable visibility.
It's a bit subtle and should be made more clear.

[lfg, 2016/07/18 17:44:00]

Yes, that interpretation is correct. I tried to clarify the comments based on
your suggestion, let me know what you think.

+  virtual bool IsHidden();
+
  protected:
   virtual ~RenderWidgetHostDelegate() {}
 };