Deliver IPC messages together with SwapCompositorFrame

content/renderer/gpu/frame_swap_message_queue.cc

Index: content/renderer/gpu/frame_swap_message_queue.cc
diff --git a/content/renderer/gpu/frame_swap_message_queue.cc b/content/renderer/gpu/frame_swap_message_queue.cc
new file mode 100644
index 0000000000000000000000000000000000000000..4306e14f791ff00c7fb6cffb92f06b612714a0b5
--- /dev/null
+++ b/content/renderer/gpu/frame_swap_message_queue.cc
@@ -0,0 +1,65 @@
+// 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 "base/logging.h"
+#include "base/stl_util.h"
+#include "ipc/ipc_message.h"
+
+using std::vector;
+
+namespace content {
+
+namespace {
+
+class SendMessageScopeImpl : public FrameSwapMessageQueue::SendMessageScope {
+ public:
+  SendMessageScopeImpl(base::Lock* lock, bool* scope_tracker)
+      : auto_lock_(*lock), auto_reset_(scope_tracker, true) {}
+  virtual ~SendMessageScopeImpl() OVERRIDE {}
+
+ private:
+  base::AutoLock auto_lock_;
+  base::AutoReset<bool> auto_reset_;
+};
+
+}  // namespace
+
+FrameSwapMessageQueue::FrameSwapMessageQueue()
+    : send_message_scope_aquired_(false) {
+}
+
+FrameSwapMessageQueue::~FrameSwapMessageQueue() {
+}
+
+void FrameSwapMessageQueue::QueueMessage(IPC::Message* msg) {
+  base::AutoLock lock(lock_);
+
+  queued_messages_.push_back(msg);
+}
+
+void FrameSwapMessageQueue::DrainMessages(
+    vector<IPC::Message>* messages) {
+  DCHECK(send_message_scope_aquired_);

[piman, 2014/05/23 20:26:36]

How about lock_.AssertAcquired()? That way you don't need
send_message_scope_aquired_, which is not thread safe if the lock is not,
actually, taken (i.e. you could have false positives).

[mkosiba (inactive), 2014/06/18 14:58:02]

Done.

+
+  for (ScopedVector<IPC::Message>::iterator i = queued_messages_.begin();
+       i != queued_messages_.end();
+       ++i) {
+    IPC::Message* m(*i);
+    messages->push_back(*m);
+  }
+  queued_messages_.clear();
+}
+
+scoped_ptr<FrameSwapMessageQueue::SendMessageScope>
+FrameSwapMessageQueue::AcquireSendMessageScope() {
+  return make_scoped_ptr(
+             new SendMessageScopeImpl(&lock_, &send_message_scope_aquired_))
+      .PassAs<SendMessageScope>();
+}
+
+}  // namespace content