cc: Set the max frames pending from the thread proxy.

cc/frame_rate_controller.h

Index: cc/frame_rate_controller.h
diff --git a/cc/frame_rate_controller.h b/cc/frame_rate_controller.h
index 16a3e37933aa5d217a0c3659c385311bfa0ba211..c302baaf4e3dc6da1bc7e0ce812dfa8c7d3d6ded 100644
--- a/cc/frame_rate_controller.h
+++ b/cc/frame_rate_controller.h
@@ -29,6 +29,8 @@ class FrameRateControllerTimeSourceAdapter;
 
 class CC_EXPORT FrameRateController {
 public:
+    static const int defaultMaxFramesPending = 2;
+
     explicit FrameRateController(scoped_refptr<TimeSource>);
     // Alternate form of FrameRateController with unthrottled frame-rate.
     explicit FrameRateController(Thread*);
@@ -48,6 +50,7 @@ public:
     void didFinishFrame();
     void didAbortAllPendingFrames();
     void setMaxFramesPending(int); // 0 for unlimited.
+    int maxFramesPending() const { return m_maxFramesPending; }
 
     // This returns null for unthrottled frame-rate.
     base::TimeTicks nextTickTime();