Deliver IPC messages together with SwapCompositorFrame

content/renderer/gpu/frame_swap_message_queue.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 "content/renderer/gpu/frame_swap_message_queue.h"
+
+#include <limits>
+
+#include "ipc/ipc_message.h"
+
+namespace content {
+
+FrameSwapMessageQueue::FrameSwapMessageQueue():
+  highest_swapped_source_frame_number_(std::numeric_limits<int>::min()) {
+}
+
+FrameSwapMessageQueue::~FrameSwapMessageQueue() {
+}
+
+void FrameSwapMessageQueue::QueueMessage(IPC::Message* msg) {
+  base::AutoLock lock(lock_);
+
+  queued_messages_[highest_swapped_source_frame_number_].push_back(msg);
+}
+
+bool FrameSwapMessageQueue::TryQueueMessage(int source_frame_number,
+                                            IPC::Message* msg) {
+  base::AutoLock lock(lock_);
+
+  if (highest_swapped_source_frame_number_ >= source_frame_number)
+    return false;
+
+  queued_messages_[source_frame_number].push_back(msg);
+  return true;
+}
+
+void FrameSwapMessageQueue::DrainMessages(int source_frame_number,
+                                          std::vector<IPC::Message>* messages) {
+  base::AutoLock lock(lock_);
+
+  DCHECK(highest_swapped_source_frame_number_ <= source_frame_number);
+  highest_swapped_source_frame_number_ = source_frame_number;
+
+  // TODO(mkosiba): rewrite before submitting.
+  for (FrameQueueMap::iterator i =
+           queued_messages_.lower_bound(source_frame_number);
+       i != queued_messages_.end() && i != queued_messages_.begin();
+       --i) {
+    for (std::vector<IPC::Message*>::iterator j = i->second.begin();
+         j != i->second.end();
+         ++j) {
+      IPC::Message* m = *j;
+      messages->push_back(*m);
+      delete m;
+    }
+    i->second.clear();
+  }
+}
+
+}  // namespace content