gpu: fix gpu process crashed on win_blink_rel due to dcheck in CopyTextureCHROMIUM.

gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.cc

 // 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 "gpu/command_buffer/service/gles2_cmd_copy_texture_chromium.h"
 
 #include <algorithm>
 
 #include "base/basictypes.h"
 #include "gpu/command_buffer/service/gl_utils.h"
@@ skipping 242 matching lines @@
 namespace gpu {
 
 CopyTextureCHROMIUMResourceManager::CopyTextureCHROMIUMResourceManager()
     : initialized_(false),
       vertex_shaders_(NUM_VERTEX_SHADERS, 0u),
       fragment_shaders_(NUM_FRAGMENT_SHADERS, 0u),
       buffer_id_(0u),
       framebuffer_(0u) {}
 
 CopyTextureCHROMIUMResourceManager::~CopyTextureCHROMIUMResourceManager() {
-  DCHECK(!buffer_id_);

[Ken Russell (switch to Gerrit), 2014/12/05 18:59:28]

Please add the comment here from the CL description about why this manager might
be deleted without releasing resources. Otherwise it's going to be difficult to
reconstruct from the version history why this was removed.

-  DCHECK(!framebuffer_);
 }
 
 void CopyTextureCHROMIUMResourceManager::Initialize(
     const gles2::GLES2Decoder* decoder) {
   COMPILE_ASSERT(
       kVertexPositionAttrib == 0u,
       Position_attribs_must_be_0);
   DCHECK(!buffer_id_);
   DCHECK(!framebuffer_);
   DCHECK(programs_.empty());
@@ skipping 198 matching lines @@
   decoder->RestoreTextureState(dest_id);
   decoder->RestoreTextureUnitBindings(0);
   decoder->RestoreActiveTexture();
   decoder->RestoreProgramBindings();
   decoder->RestoreBufferBindings();
   decoder->RestoreFramebufferBindings();
   decoder->RestoreGlobalState();
 }
 
 }  // namespace gpu