Parameterize TaskRunner used by ui::Compositor

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index f6ed688d9b405aba456f7d12bea4dcc604afefbd..603bf487ed24351e78771d66954301522a63d3cb 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -44,7 +44,7 @@ namespace ui {
 
 CompositorLock::CompositorLock(Compositor* compositor)
     : compositor_(compositor) {
-  base::MessageLoop::current()->PostDelayedTask(
+  compositor_->task_runner_->PostDelayedTask(
       FROM_HERE,
       base::Bind(&CompositorLock::CancelLock, AsWeakPtr()),
       base::TimeDelta::FromMilliseconds(kCompositorLockTimeoutMs));
@@ -70,11 +70,13 @@ namespace {
 namespace ui {
 
 Compositor::Compositor(gfx::AcceleratedWidget widget,
-                       ui::ContextFactory* context_factory)
+                       ui::ContextFactory* context_factory,
+                       scoped_refptr<base::SingleThreadTaskRunner> task_runner)
     : context_factory_(context_factory),
       root_layer_(NULL),
       widget_(widget),
       compositor_thread_loop_(context_factory->GetCompositorMessageLoop()),
+      task_runner_(task_runner),
       vsync_manager_(new CompositorVSyncManager()),
       device_scale_factor_(0.0f),
       last_started_frame_(0),
@@ -142,7 +144,7 @@ Compositor::Compositor(gfx::AcceleratedWidget widget,
         this,
         context_factory_->GetSharedBitmapManager(),
         settings,
-        base::MessageLoopProxy::current(),
+        task_runner_,
         compositor_thread_loop_);
   } else {
     host_ = cc::LayerTreeHost::CreateSingleThreaded(
@@ -150,7 +152,7 @@ Compositor::Compositor(gfx::AcceleratedWidget widget,
         this,
         context_factory_->GetSharedBitmapManager(),
         settings,
-        base::MessageLoopProxy::current());
+        task_runner_);
   }
   UMA_HISTOGRAM_TIMES("GPU.CreateBrowserCompositor",
                       base::TimeTicks::Now() - before_create);
@@ -179,7 +181,7 @@ void Compositor::ScheduleDraw() {
     host_->SetNeedsCommit();
   } else if (!defer_draw_scheduling_) {
     defer_draw_scheduling_ = true;
-    base::MessageLoop::current()->PostTask(
+    task_runner_->PostTask(
         FROM_HERE,
         base::Bind(&Compositor::Draw, schedule_draw_factory_.GetWeakPtr()));
   }