Add compositing, layers to app_list_demo

ui/views/cocoa/bridged_content_view.mm

 // Copyright 2014 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.
 
 #import "ui/views/cocoa/bridged_content_view.h"
 
 #include "base/logging.h"
 #import "base/mac/scoped_nsobject.h"
 #include "base/strings/sys_string_conversions.h"
 #include "ui/base/ime/text_input_client.h"
@@ skipping 71 matching lines @@
 
 - (void)setFrameSize:(NSSize)newSize {
   [super setFrameSize:newSize];
   if (!hostedView_)
     return;
 
   hostedView_->SetSize(gfx::Size(newSize.width, newSize.height));
 }
 
 - (void)drawRect:(NSRect)dirtyRect {
-  if (!hostedView_)
+  if (!hostedView_ || [self wantsLayer])
     return;
 
   gfx::CanvasSkiaPaint canvas(dirtyRect, false /* opaque */);
   hostedView_->Paint(&canvas, views::CullSet());
 }
 
 // NSResponder implementation.
 
 - (void)keyDown:(NSEvent*)theEvent {
   if (textInputClient_)
@@ skipping 208 matching lines @@
   }
 
   return [super accessibilityAttributeValue:attribute];
 }
 
 - (id)accessibilityHitTest:(NSPoint)point {
   return [hostedView_->GetNativeViewAccessible() accessibilityHitTest:point];
 }
 
 @end