ui/compositor: move the browser compositor thread to the ContextFactory

content/browser/compositor/gpu_process_transport_factory.cc

Index: content/browser/compositor/gpu_process_transport_factory.cc
diff --git a/content/browser/compositor/gpu_process_transport_factory.cc b/content/browser/compositor/gpu_process_transport_factory.cc
index 16f600a85ae6e110687acf2b3f764ceb78733d51..9e56e8436fea737b6228f12456d1c9ec77c0c96a 100644
--- a/content/browser/compositor/gpu_process_transport_factory.cc
+++ b/content/browser/compositor/gpu_process_transport_factory.cc
@@ -11,6 +11,7 @@
 #include "base/location.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
+#include "base/threading/thread.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/output_surface.h"
 #include "content/browser/compositor/browser_compositor_output_surface.h"
@@ -62,6 +63,16 @@ GpuProcessTransportFactory::GpuProcessTransportFactory()
     : callback_factory_(this) {
   output_surface_proxy_ = new BrowserCompositorOutputSurfaceProxy(
       &output_surface_map_);
+#if defined(OS_CHROMEOS)
+  bool use_thread = !CommandLine::ForCurrentProcess()->HasSwitch(
+      switches::kUIDisableThreadedCompositing);
+#else
+  bool use_thread = false;
+#endif
+  if (use_thread) {
+    compositor_thread_.reset(new base::Thread("Browser Compositor"));
+    compositor_thread_->Start();
+  }
 }
 
 GpuProcessTransportFactory::~GpuProcessTransportFactory() {
@@ -69,6 +80,11 @@ GpuProcessTransportFactory::~GpuProcessTransportFactory() {
 
   // Make sure the lost context callback doesn't try to run during destruction.
   callback_factory_.InvalidateWeakPtrs();
+
+  if (compositor_thread_.get()) {
+    compositor_thread_->Stop();

[danakj, 2014/05/08 22:37:30]

Why do we need to do Stop() and reset()? The destructor does this already right?
They're redundant here, and also with the default cleanup the class does?

[piman, 2014/05/08 22:48:34]

Done. I was just copy&pasting from existing code that was Stop()ing before
deleting, but I see that there's no need for that.

+    compositor_thread_.reset();
+  }
 }
 
 scoped_ptr<WebGraphicsContext3DCommandBufferImpl>
@@ -134,7 +150,7 @@ scoped_ptr<cc::OutputSurface> GpuProcessTransportFactory::CreateOutputSurface(
   UMA_HISTOGRAM_BOOLEAN("Aura.CreatedGpuBrowserCompositor", !!context_provider);
 
   if (!context_provider.get()) {
-    if (ui::Compositor::WasInitializedWithThread()) {
+    if (compositor_thread_.get()) {
       LOG(FATAL) << "Failed to create UI context, but can't use software"
                  " compositing with browser threaded compositing. Aborting.";
     }
@@ -150,7 +166,7 @@ scoped_ptr<cc::OutputSurface> GpuProcessTransportFactory::CreateOutputSurface(
   }
 
   scoped_refptr<base::SingleThreadTaskRunner> compositor_thread_task_runner =
-      ui::Compositor::GetCompositorMessageLoop();
+      GetCompositorMessageLoop();
   if (!compositor_thread_task_runner.get())
     compositor_thread_task_runner = base::MessageLoopProxy::current();
 
@@ -178,8 +194,11 @@ scoped_refptr<ui::Reflector> GpuProcessTransportFactory::CreateReflector(
   PerCompositorData* data = per_compositor_data_[source];
   DCHECK(data);
 
-  data->reflector = new ReflectorImpl(
-      source, target, &output_surface_map_, data->surface_id);
+  data->reflector = new ReflectorImpl(source,
+                                      target,
+                                      &output_surface_map_,
+                                      GetCompositorMessageLoop(),
+                                      data->surface_id);
   return data->reflector;
 }
 
@@ -222,6 +241,12 @@ cc::SharedBitmapManager* GpuProcessTransportFactory::GetSharedBitmapManager() {
   return HostSharedBitmapManager::current();
 }
 
+base::MessageLoopProxy* GpuProcessTransportFactory::GetCompositorMessageLoop() {
+  if (!compositor_thread_)
+    return NULL;
+  return compositor_thread_->message_loop_proxy();
+}
+
 gfx::GLSurfaceHandle GpuProcessTransportFactory::GetSharedSurfaceHandle() {
   gfx::GLSurfaceHandle handle = gfx::GLSurfaceHandle(
       gfx::kNullPluginWindow, gfx::TEXTURE_TRANSPORT);