Add occlusion support to WebContentsImpl and RenderWidgetHostView

content/public/browser/render_widget_host_view.h

Index: content/public/browser/render_widget_host_view.h
diff --git a/content/public/browser/render_widget_host_view.h b/content/public/browser/render_widget_host_view.h
index 6d97fd898ef8fba1ae5dc1034ab169d6deddc8ee..8758c501ba35c666223df574a394f583d5483bed 100644
--- a/content/public/browser/render_widget_host_view.h
+++ b/content/public/browser/render_widget_host_view.h
@@ -93,6 +93,14 @@ class CONTENT_EXPORT RenderWidgetHostView {
   // 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;