Mac: Remove white CALayers

content/browser/renderer_host/render_widget_host_view_mac.h

Index: content/browser/renderer_host/render_widget_host_view_mac.h
diff --git a/content/browser/renderer_host/render_widget_host_view_mac.h b/content/browser/renderer_host/render_widget_host_view_mac.h
index 5437503df3e73bfc6b8183e992c292b36e279e51..68008637b440420bd9f1a7ad232fbbc084ba7bcf 100644
--- a/content/browser/renderer_host/render_widget_host_view_mac.h
+++ b/content/browser/renderer_host/render_widget_host_view_mac.h
@@ -556,8 +556,9 @@ class CONTENT_EXPORT RenderWidgetHostViewMac
   // Whether a request to flush input has been issued.
   bool needs_flush_input_;
 
-  // The background color of the web content.
-  SkColor background_color_;
+  // The background color of the web content. This color will be drawn when the
+  // web content is not able to draw in time.
+  SkColor background_color_ = SK_ColorTRANSPARENT;
 
   // Factory used to safely scope delayed calls to ShutdownHost().
   base::WeakPtrFactory<RenderWidgetHostViewMac> weak_factory_;