Send input event IPCs directly from the UI thread

ipc/ipc_channel_proxy.cc

Index: ipc/ipc_channel_proxy.cc
diff --git a/ipc/ipc_channel_proxy.cc b/ipc/ipc_channel_proxy.cc
index b3424124158d5034c5cd142c8779a81c17c83923..4fd8a9aa02cb268217b948660cbdffd6f9f272e3 100644
--- a/ipc/ipc_channel_proxy.cc
+++ b/ipc/ipc_channel_proxy.cc
@@ -318,23 +318,20 @@ void ChannelProxy::Context::ClearChannel() {
   channel_.reset();
 }
 
-void ChannelProxy::Context::SendFromThisThread(Message* message) {
-  base::AutoLock l(channel_lifetime_lock_);
-  if (!channel_)
-    return;
-  DCHECK(channel_->IsSendThreadSafe());
-  channel_->Send(message);
-}
-
-void ChannelProxy::Context::Send(Message* message) {
-  if (channel_send_thread_safe_) {
-    SendFromThisThread(message);
-    return;
+bool ChannelProxy::Context::Send(std::unique_ptr<Message> message,
+                                 bool force_io_thread) {
+  if (channel_send_thread_safe_ && !force_io_thread) {
+    base::AutoLock l(channel_lifetime_lock_);
+    if (!channel_)
+      return false;
+    DCHECK(channel_->IsSendThreadSafe());
+    return channel_->Send(message.release());
   }
 
   ipc_task_runner()->PostTask(
       FROM_HERE, base::Bind(&ChannelProxy::Context::OnSendMessage, this,
-                            base::Passed(base::WrapUnique(message))));
+                            base::Passed(&message)));
+  return true;
 }
 
 bool ChannelProxy::Context::IsChannelSendThreadSafe() const {
@@ -377,11 +374,7 @@ ChannelProxy::ChannelProxy(Context* context)
 ChannelProxy::ChannelProxy(
     Listener* listener,
     const scoped_refptr<base::SingleThreadTaskRunner>& ipc_task_runner)
-    : context_(new Context(listener, ipc_task_runner)), did_init_(false) {
-#if defined(ENABLE_IPC_FUZZER)
-  outgoing_message_filter_ = NULL;
-#endif
-}
+    : ChannelProxy(new Context(listener, ipc_task_runner)) {}
 
 ChannelProxy::~ChannelProxy() {
   DCHECK(CalledOnValidThread());
@@ -444,25 +437,15 @@ void ChannelProxy::Close() {
 }
 
 bool ChannelProxy::Send(Message* message) {
-  DCHECK(did_init_);
-
-  // TODO(alexeypa): add DCHECK(CalledOnValidThread()) here. Currently there are
-  // tests that call Send() from a wrong thread. See http://crbug.com/163523.
-
-#ifdef ENABLE_IPC_FUZZER
-  // In IPC fuzzing builds, it is possible to define a filter to apply to
-  // outgoing messages. It will either rewrite the message and return a new
-  // one, freeing the original, or return the message unchanged.
-  if (outgoing_message_filter())
-    message = outgoing_message_filter()->Rewrite(message);
-#endif
+  return SendImpl(base::WrapUnique(message), true /* force_io_thread */);
+}
 
-#ifdef IPC_MESSAGE_LOG_ENABLED
-  Logging::GetInstance()->OnSendMessage(message, context_->channel_id());
-#endif
+bool ChannelProxy::SendNow(std::unique_ptr<Message> message) {
+  return SendImpl(std::move(message), false /* force_io_thread */);
+}
 
-  context_->Send(message);
-  return true;
+bool ChannelProxy::SendOnIPCThread(std::unique_ptr<Message> message) {
+  return SendImpl(std::move(message), true /* force_io_thread */);
 }
 
 void ChannelProxy::AddFilter(MessageFilter* filter) {
@@ -519,6 +502,28 @@ base::ScopedFD ChannelProxy::TakeClientFileDescriptor() {
 void ChannelProxy::OnChannelInit() {
 }
 
+bool ChannelProxy::SendImpl(std::unique_ptr<Message> message,
+                            bool force_io_thread) {
+  DCHECK(did_init_);
+
+  // TODO(alexeypa): add DCHECK(CalledOnValidThread()) here. Currently there are
+  // tests that call Send() from a wrong thread. See http://crbug.com/163523.
+
+#ifdef ENABLE_IPC_FUZZER
+  // In IPC fuzzing builds, it is possible to define a filter to apply to
+  // outgoing messages. It will either rewrite the message and return a new
+  // one, freeing the original, or return the message unchanged.
+  if (outgoing_message_filter())
+    message.reset(outgoing_message_filter()->Rewrite(message.release()));
+#endif
+
+#ifdef IPC_MESSAGE_LOG_ENABLED
+  Logging::GetInstance()->OnSendMessage(message.get(), context_->channel_id());
+#endif
+
+  return context_->Send(std::move(message), force_io_thread);
+}
+
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC