Use solid color layer for delegated surface.

ash/display/mirror_window_controller.cc

 // Copyright (c) 2013 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 "ash/display/mirror_window_controller.h"
 
 #if defined(USE_X11)
 #include <X11/Xlib.h>
 #include <X11/extensions/XInput2.h>
 
@@ skipping 95 matching lines @@
     host->InitHost();
 #if defined(USE_X11)
     DisableInput(host->GetAcceleratedWidget());
 #endif
 
     aura::client::SetCaptureClient(host->window(), new NoneCaptureClient());
     host->Show();
 
     // TODO(oshima): Start mirroring.
     aura::Window* mirror_window = new aura::Window(NULL);
-    mirror_window->Init(aura::WINDOW_LAYER_TEXTURED);
+    mirror_window->Init(aura::WINDOW_LAYER_SOLID_COLOR);

[sky, 2014/10/10 02:42:57]

Why is solid color right here?

     host->window()->AddChild(mirror_window);
     mirror_window->SetBounds(host->window()->bounds());
     mirror_window->Show();
     reflector_ = aura::Env::GetInstance()->context_factory()->CreateReflector(
         Shell::GetPrimaryRootWindow()->GetHost()->compositor(),
         mirror_window->layer());
   } else {
     aura::WindowTreeHost* host = ash_host_->AsWindowTreeHost();
     GetRootWindowSettings(host->window())->display_id = display_info.id();
     host->SetBounds(display_info.bounds_in_native());
@@ skipping 55 matching lines @@
       display_manager->mirrored_display_id());
   const DisplayInfo& source_display_info = display_manager->GetDisplayInfo(
       Shell::GetScreen()->GetPrimaryDisplay().id());
   DCHECK(display_manager->IsMirrored());
   return scoped_ptr<RootWindowTransformer>(
       CreateRootWindowTransformerForMirroredDisplay(source_display_info,
                                                     mirror_display_info));
 }
 
 }  // namespace ash