cc: Use BeginFrameArgs

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 2ebf5c000ae3ddbdeea691269f86fa8fa47f00ab..82d2a5713e5e671f81781851686c921817e059bf 100644
--- a/cc/trees/thread_proxy.cc
+++ b/cc/trees/thread_proxy.cc
@@ -1045,6 +1045,25 @@ void ThreadProxy::DidAnticipatedDrawTimeChange(base::TimeTicks time) {
   layer_tree_host_impl_->ResetCurrentFrameTimeForNextFrame();
 }
 
+
+void ThreadProxy::PostBeginFrameDeadlineTask(base::TimeTicks deadline) {
+  base::TimeDelta delta = deadline - base::TimeTicks::Now();

[ajuma, 2013/06/14 15:22:32]

To get a sufficiently precise delta on Windows, we'll need HighResNow() (also
when calculating the deadline itself).

[brianderson, 2013/06/14 18:42:36]

Ok. We'll have to be very careful about comparing HighResNow() and Now().
@simonjam mentioned that base::TimeTicks makes an attempt to keep them
comparable, but I'm not sure we can trust it.

Also, HighResNow doesn't work very well on some old Windows+CPU+driver
combinations - the result isn't monotonically increasing if called on different
cores.

+  if (delta <= base::TimeDelta()) {
+    scheduler_on_impl_thread_->OnBeginFrameDeadline();
+    return;
+  }
+
+  Proxy::ImplThread()->PostDelayedTask(

[Sami, 2013/06/14 15:59:20]

Can/should we cancel this task if we drew before the deadline?

[brianderson, 2013/06/14 18:42:36]

It's kind of "canceled" manually based on the begin_frame_state_. Is there a way
to cancel it so that it doesn't even wake up the thread?

+      base::Bind(&ThreadProxy::OnBeginFrameDeadline,
+                 weak_factory_on_impl_thread_.GetWeakPtr()),
+      deadline - base::TimeTicks::Now());

[ajuma, 2013/06/14 15:22:32]

We can reuse |delta| here.

[brianderson, 2013/06/14 18:42:36]

oops!

+}
+
+void ThreadProxy::OnBeginFrameDeadline() {
+  DCHECK(IsImplThread());
+  scheduler_on_impl_thread_->OnBeginFrameDeadline();
+}
+
 void ThreadProxy::ReadyToFinalizeTextureUpdates() {
   DCHECK(IsImplThread());
   scheduler_on_impl_thread_->FinishCommit();