ozone: Dispatch GPU process IPCs to IO thread directly from GpuPlatformSupportHost

ui/ozone/platform/dri/dri_gpu_platform_support_host.cc

Index: ui/ozone/platform/dri/dri_gpu_platform_support_host.cc
diff --git a/ui/ozone/platform/dri/dri_gpu_platform_support_host.cc b/ui/ozone/platform/dri/dri_gpu_platform_support_host.cc
index 890ee325c5aff3b3bcd63a0cf5bc555256f373a7..eb1d6b91aa1d8b9b04d82a55059851171d40e4a9 100644
--- a/ui/ozone/platform/dri/dri_gpu_platform_support_host.cc
+++ b/ui/ozone/platform/dri/dri_gpu_platform_support_host.cc
@@ -11,8 +11,7 @@
 
 namespace ui {
 
-DriGpuPlatformSupportHost::DriGpuPlatformSupportHost()
-    : host_id_(-1), sender_(NULL) {
+DriGpuPlatformSupportHost::DriGpuPlatformSupportHost() : host_id_(-1) {
 }
 
 DriGpuPlatformSupportHost::~DriGpuPlatformSupportHost() {
@@ -22,8 +21,8 @@ void DriGpuPlatformSupportHost::RegisterHandler(
     GpuPlatformSupportHost* handler) {
   handlers_.push_back(handler);
 
-  if (sender_)
-    handler->OnChannelEstablished(host_id_, sender_);
+  if (IsConnected())
+    handler->OnChannelEstablished(host_id_, send_runner_, send_callback_);
 }
 
 void DriGpuPlatformSupportHost::UnregisterHandler(
@@ -37,7 +36,7 @@ void DriGpuPlatformSupportHost::UnregisterHandler(
 void DriGpuPlatformSupportHost::AddChannelObserver(ChannelObserver* observer) {
   channel_observers_.AddObserver(observer);
 
-  if (sender_)
+  if (IsConnected())
     observer->OnChannelEstablished();
 }
 
@@ -46,15 +45,22 @@ void DriGpuPlatformSupportHost::RemoveChannelObserver(
   channel_observers_.RemoveObserver(observer);
 }
 
-void DriGpuPlatformSupportHost::OnChannelEstablished(int host_id,
-                                                     IPC::Sender* sender) {
+bool DriGpuPlatformSupportHost::IsConnected() {
+  return host_id_ >= 0;
+}
+
+void DriGpuPlatformSupportHost::OnChannelEstablished(
+    int host_id,
+    scoped_refptr<base::SingleThreadTaskRunner> send_runner,
+    const base::Callback<void(IPC::Message*)>& send_callback) {
   TRACE_EVENT1("dri", "DriGpuPlatformSupportHost::OnChannelEstablished",
                "host_id", host_id);
   host_id_ = host_id;
-  sender_ = sender;
+  send_runner_ = send_runner;
+  send_callback_ = send_callback;
 
   for (size_t i = 0; i < handlers_.size(); ++i)
-    handlers_[i]->OnChannelEstablished(host_id, sender);
+    handlers_[i]->OnChannelEstablished(host_id, send_runner_, send_callback_);
 
   FOR_EACH_OBSERVER(ChannelObserver, channel_observers_,
                     OnChannelEstablished());
@@ -65,8 +71,8 @@ void DriGpuPlatformSupportHost::OnChannelDestroyed(int host_id) {
                "host_id", host_id);
   if (host_id_ == host_id) {
     host_id_ = -1;
-    sender_ = NULL;
-
+    send_runner_ = nullptr;
+    send_callback_.Reset();
     FOR_EACH_OBSERVER(ChannelObserver, channel_observers_,
                       OnChannelDestroyed());
   }
@@ -84,9 +90,11 @@ bool DriGpuPlatformSupportHost::OnMessageReceived(const IPC::Message& message) {
 }
 
 bool DriGpuPlatformSupportHost::Send(IPC::Message* message) {
-  if (sender_)
-    return sender_->Send(message);
+  if (IsConnected() &&
+      send_runner_->PostTask(FROM_HERE, base::Bind(send_callback_, message)))
+    return true;
 
+  delete message;
   return false;
 }