Add occlusion support to WebContentsImpl and RenderWidgetHostView

content/public/browser/render_widget_host_view.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_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 #define CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_
 
 #include "base/basictypes.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/strings/string16.h"
@@ skipping 75 matching lines @@
   virtual bool IsSurfaceAvailableForCopy() const = 0;
 
   // Shows/hides the view.  These must always be called together in pairs.
   // It is not legal to call Hide() multiple times in a row.
   virtual void Show() = 0;
   virtual void Hide() = 0;
 
   // Whether the view is showing.
   virtual bool IsShowing() = 0;
 
+  // Indicates if the view is currently occluded (e.g, not visible because it's
+  // covered up by other windows on Mac), and as a result the view's renderer

[Avi (use Gerrit), 2015/01/16 21:47:11]

Occlusion is a phenomenon that happens on all platforms, not just on the Mac.
Pull the "on Mac" part out of the parentheses. You can say that these functions
are called only on the Mac for now.

[ccameron, 2015/01/16 21:54:07]

Updated (I left a sentence at the end saying it's just for Mac, but I'm hoping
to throw support for this into ash as well).

+  // may be suspended. If Show() is called on a view then its state should be
+  // re-set to being un-occluded (an explicit WasUnOccluded call will not be
+  // made for that). These calls are not necessarily made in pairs.
+  virtual void WasUnOccluded() = 0;
+  virtual void WasOccluded() = 0;
+
   // Retrieve the bounds of the View, in screen coordinates.
   virtual gfx::Rect GetViewBounds() const = 0;
 
   // Returns true if the View's context menu is showing.
   virtual bool IsShowingContextMenu() const = 0;
 
   // Tells the View whether the context menu is showing.
   virtual void SetShowingContextMenu(bool showing) = 0;
 
   // Returns the currently selected text.
@@ skipping 57 matching lines @@
   // Returns |true| if text is currently being spoken by Mac OS X.
   virtual bool IsSpeaking() const = 0;
   // Stops speaking, if it is currently in progress.
   virtual void StopSpeaking() = 0;
 #endif  // defined(OS_MACOSX)
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RENDER_WIDGET_HOST_VIEW_H_