Forward input tasks to the Blink scheduler

cc/trees/thread_proxy.cc

Index: cc/trees/thread_proxy.cc
diff --git a/cc/trees/thread_proxy.cc b/cc/trees/thread_proxy.cc
index 56ce577b9d65110eda1e33f3f53a9992f558aabe..751ecaeb46b9add7e880a5dfb45a7ee16d8c3018 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -61,15 +61,19 @@ struct ThreadProxy::SchedulerStateRequest {
 
 scoped_ptr<Proxy> ThreadProxy::Create(
     LayerTreeHost* layer_tree_host,
+    scoped_refptr<cc::MainThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner) {
-  return make_scoped_ptr(new ThreadProxy(layer_tree_host, impl_task_runner))
+  return make_scoped_ptr(new ThreadProxy(layer_tree_host,
+                                         main_task_runner,
+                                         impl_task_runner))
       .PassAs<Proxy>();
 }
 
 ThreadProxy::ThreadProxy(
     LayerTreeHost* layer_tree_host,
+    scoped_refptr<cc::MainThreadTaskRunner> main_task_runner,
     scoped_refptr<base::SingleThreadTaskRunner> impl_task_runner)
-    : Proxy(impl_task_runner),
+    : Proxy(main_task_runner, impl_task_runner),
       main_thread_only_vars_unsafe_(this, layer_tree_host->id()),
       main_thread_or_blocked_vars_unsafe_(layer_tree_host),
       compositor_thread_vars_unsafe_(this, layer_tree_host->id()) {
@@ -462,12 +466,14 @@ void ThreadProxy::SetDeferCommits(bool defer_commits) {
   else
     TRACE_EVENT_ASYNC_END0("cc", "ThreadProxy::SetDeferCommits", this);
 
-  if (!main().defer_commits && main().pending_deferred_commit)
-    Proxy::MainThreadTaskRunner()->PostTask(
+  if (!main().defer_commits && main().pending_deferred_commit) {
+    Proxy::MainThreadTaskRunner()->PostBeginMainFrameTask(
         FROM_HERE,
         base::Bind(&ThreadProxy::BeginMainFrame,
                    main_thread_weak_ptr_,
-                   base::Passed(&main().pending_deferred_commit)));
+                   base::Passed(&main().pending_deferred_commit)),
+        0, 0, 0);
+  }
 }
 
 bool ThreadProxy::CommitRequested() const {
@@ -705,11 +711,12 @@ void ThreadProxy::ScheduledActionSendBeginMainFrame() {
       impl().layer_tree_host_impl->memory_allocation_priority_cutoff();
   begin_main_frame_state->evicted_ui_resources =
       impl().layer_tree_host_impl->EvictedUIResourcesExist();
-  Proxy::MainThreadTaskRunner()->PostTask(
+  Proxy::MainThreadTaskRunner()->PostBeginMainFrameTask(
       FROM_HERE,
       base::Bind(&ThreadProxy::BeginMainFrame,
                  main_thread_weak_ptr_,
-                 base::Passed(&begin_main_frame_state)));
+                 base::Passed(&begin_main_frame_state)),
+      0, 0, 0);

[mithro-old, 2014/07/08 11:18:51]

This line I don't quite understand? Isn't all the state you are passing as
arguments actually captured in the begin_main_frame_state structure?

I have a CL which I'm yet to send out which changes that structure to use a
complete BeginFrameArgs rather than just a TimeTicks object.

[Sami, 2014/07/08 11:23:15]

Yes, the data is inside begin_main_frame_state, but since it's wrapped up in a
closure the scheduler can't see it. Because of that we need to also pass in the
relevant timestamps next to the task itself.

If BeginFrameArgs could survive a round-trip through blink then the scheduler
could just pass it back as an argument for the callback, but I'm not sure that's
necessary.

   devtools_instrumentation::DidRequestMainThreadFrame(
       impl().layer_tree_host_id);
   impl().timing_history.DidBeginMainFrame();