zero-copy: Clarify to allocate/destroy GpuMemoryBuffer on any thread and use it on the main thread o

ui/ozone/platform/caca/caca_window_manager.cc

 // 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.
 
 #include "ui/ozone/platform/caca/caca_window_manager.h"
 
 #include "base/trace_event/trace_event.h"
 #include "third_party/skia/include/core/SkCanvas.h"
 #include "third_party/skia/include/core/SkSurface.h"
 #include "ui/gfx/skia_util.h"
@@ skipping 100 matching lines @@
 int32_t CacaWindowManager::AddWindow(CacaWindow* window) {
   return windows_.Add(window);
 }
 
 void CacaWindowManager::RemoveWindow(int window_id, CacaWindow* window) {
   DCHECK_EQ(window, windows_.Lookup(window_id));
   windows_.Remove(window_id);
 }
 
 CacaWindowManager::~CacaWindowManager() {
+  DCHECK(thread_checker_.CalledOnValidThread());

[reveman, 2015/04/07 13:07:05]

how are the DCHECKs in this file related to GpuMemoryBuffer usage on one thread?

 }
 
 bool CacaWindowManager::LoadEGLGLES2Bindings(
     AddGLLibraryCallback add_gl_library,
     SetGLGetProcAddressProcCallback set_gl_get_proc_address) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   return false;
 }
 
 scoped_ptr<ui::SurfaceOzoneCanvas> CacaWindowManager::CreateCanvasForWidget(
     gfx::AcceleratedWidget widget) {
+  DCHECK(thread_checker_.CalledOnValidThread());
   CacaWindow* window = windows_.Lookup(widget);
   DCHECK(window);
 
   scoped_ptr<CacaSurface> canvas(new CacaSurface(window));
   bool initialized = canvas->Initialize();
   DCHECK(initialized);
   return canvas.Pass();
 }
 
 }  // namespace ui