Use solid color layer for delegated surface.

content/browser/renderer_host/render_widget_host_view_mac.mm

 // 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.
 
 #include "content/browser/renderer_host/render_widget_host_view_mac.h"
 
 #import <objc/runtime.h>
 #include <OpenGL/gl.h>
 #include <QuartzCore/QuartzCore.h>
 
@@ skipping 528 matching lines @@
 
   // Make this view host a solid white layer when there is no content ready to
   // draw.
   background_layer_.reset([[CALayer alloc] init]);
   [background_layer_
       setBackgroundColor:CGColorGetConstantColor(kCGColorWhite)];
   [cocoa_view_ setLayer:background_layer_];
   [cocoa_view_ setWantsLayer:YES];
 
   if (IsDelegatedRendererEnabled()) {
-    root_layer_.reset(new ui::Layer(ui::LAYER_TEXTURED));
+    root_layer_.reset(new ui::Layer(ui::LAYER_SOLID_COLOR));
     delegated_frame_host_.reset(new DelegatedFrameHost(this));
   }
 
   gfx::Screen::GetScreenFor(cocoa_view_)->AddObserver(this);
 
   render_widget_host_->SetView(this);
 }
 
 RenderWidgetHostViewMac::~RenderWidgetHostViewMac() {
   gfx::Screen::GetScreenFor(cocoa_view_)->RemoveObserver(this);
@@ skipping 2757 matching lines @@
 
 // "-webkit-app-region: drag | no-drag" is implemented on Mac by excluding
 // regions that are not draggable. (See ControlRegionView in
 // native_app_window_cocoa.mm). This requires the render host view to be
 // draggable by default.
 - (BOOL)mouseDownCanMoveWindow {
   return YES;
 }
 
 @end