cc: Fix infinite BeginFrame that Scheduler causes.

cc/scheduler/scheduler.cc

Index: cc/scheduler/scheduler.cc
diff --git a/cc/scheduler/scheduler.cc b/cc/scheduler/scheduler.cc
index 8329e8e9601b823f1293d842f7e55ed4fe7a40fe..3e85eb9c364ff4c1e700b4ae62b5d5d31088c275 100644
--- a/cc/scheduler/scheduler.cc
+++ b/cc/scheduler/scheduler.cc
@@ -133,7 +133,9 @@ void Scheduler::SetupNextBeginFrameIfNeeded() {
   bool proactive_begin_frame_wanted =
       state_machine_.ProactiveBeginFrameWantedByImplThread() &&
       !settings_.using_synchronous_renderer_compositor;
-  bool needs_begin_frame = needs_begin_frame_to_draw ||
+  bool needs_begin_frame = state_machine_.inside_begin_frame() ?
+                           needs_begin_frame_to_draw :
+                           needs_begin_frame_to_draw ||

[dshwang, 2013/06/24 18:53:20]

"state_machine_.inside_begin_frame() is true" means that COMMIT is performed
now. So we don't need to be proactive.

Moreover, being proactive removes the chance to disable "reserved BeginFrame".

                            proactive_begin_frame_wanted;
   bool immediate_disables_needed =
       settings_.using_synchronous_renderer_compositor;