Fix for jankiness in some accelerated 2D canvas demos: If there is already a...

gpu/command_buffer/client/gles2_implementation.cc

 // Copyright (c) 2009 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.
 
 // A class to emluate GLES2 over command buffers.
 
 #include "../client/gles2_implementation.h"
 #include <GLES2/gles2_command_buffer.h>
 #include "../client/mapped_memory.h"
 #include "../common/gles2_cmd_utils.h"
@@ skipping 671 matching lines @@
   // Wait if this would add too many swap buffers.
   if (swap_buffers_tokens_.size() == kMaxSwapBuffers) {
     helper_->WaitForToken(swap_buffers_tokens_.front());
     swap_buffers_tokens_.pop();
   }
   helper_->SwapBuffers();
   swap_buffers_tokens_.push(helper_->InsertToken());
   Flush();
 }
 
+void GLES2Implementation::CopyTextureToParentTextureCHROMIUM(
+    GLuint client_child_id, GLuint client_parent_id) {
+  // Wait if this would add too many CopyTextureToParentTexture's
+  if (swap_buffers_tokens_.size() == kMaxSwapBuffers) {
+    helper_->WaitForToken(swap_buffers_tokens_.front());
+    swap_buffers_tokens_.pop();
+  }
+  helper_->CopyTextureToParentTextureCHROMIUM(client_child_id,
+      client_parent_id);
+  swap_buffers_tokens_.push(helper_->InsertToken());
+  Flush();
+}
+
 void GLES2Implementation::GenSharedIdsCHROMIUM(
   GLuint namespace_id, GLuint id_offset, GLsizei n, GLuint* ids) {
   GLint* id_buffer = transfer_buffer_.AllocTyped<GLint>(n);
   helper_->GenSharedIdsCHROMIUM(namespace_id, id_offset, n,
                         transfer_buffer_id_,
                         transfer_buffer_.GetOffset(id_buffer));
   WaitForCmd();
   memcpy(ids, id_buffer, sizeof(*ids) * n);
   transfer_buffer_.FreePendingToken(id_buffer, helper_->InsertToken());
 }
@@ skipping 939 matching lines @@
 }
 
 void GLES2Implementation::RequestExtensionCHROMIUM(const char* extension) {
   SetBucketAsCString(kResultBucketId, extension);
   helper_->RequestExtensionCHROMIUM(kResultBucketId);
   helper_->SetBucketSize(kResultBucketId, 0);
 }
 
 }  // namespace gles2
 }  // namespace gpu