gpu: Allow CopyTexImage to be called with StreamTextures and GLImageSync.

gpu/command_buffer/service/texture_definition.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 "gpu/command_buffer/service/texture_definition.h"
 
 #include <list>
 
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 67 matching lines @@
 bool GLImageSync::BindTexImage(unsigned target) {
   NOTREACHED();
   return false;
 }
 
 void GLImageSync::ReleaseTexImage(unsigned target) {
   NOTREACHED();
 }
 
 bool GLImageSync::CopyTexImage(unsigned target) {
-  NOTREACHED();
   return false;
 }
 
 void GLImageSync::WillUseTexImage() {
   if (buffer_.get())
     buffer_->WillRead(this);
 }
 
 void GLImageSync::DidUseTexImage() {
   if (buffer_.get())
@@ skipping 394 matching lines @@
 
   // All structural changes should have orphaned the texture.
   if (image_buffer_.get() && !texture->GetLevelImage(texture->target(), 0))
     return false;
 
   return true;
 }
 
 }  // namespace gles2
 }  // namespace gpu