cc: Use BeginFrameArgs

cc/scheduler/scheduler_state_machine.h

Index: cc/scheduler/scheduler_state_machine.h
diff --git a/cc/scheduler/scheduler_state_machine.h b/cc/scheduler/scheduler_state_machine.h
index 3784f6f3763391c656516ee448c2615e5ea6a474..bf797bb7b49a3942e1e5df2891828d4bac6449b4 100644
--- a/cc/scheduler/scheduler_state_machine.h
+++ b/cc/scheduler/scheduler_state_machine.h
@@ -31,10 +31,18 @@ class CC_EXPORT SchedulerStateMachine {
   // settings must be valid for the lifetime of this class.
   explicit SchedulerStateMachine(const SchedulerSettings& settings);
 
+  enum BeginFrameState {

[brianderson, 2013/06/21 01:27:20]

Note: This version of the patch enforces the rule that the BeginFrameState will
always cycle through all the states in order, whether or not it actually waits
or draws. It will at least *try* to wait or *try* to draw in those states.

I found it easier to reason about than the branching state sequence of the first
patch.

I will add a comment about this.

+    BEGIN_FRAME_IDLE,
+    BEGIN_FRAME_STARTING,
+    BEGIN_FRAME_WAITING,
+    BEGIN_FRAME_DRAWING,
+  };
+
   enum CommitState {
     COMMIT_STATE_IDLE,
     COMMIT_STATE_FRAME_IN_PROGRESS,
     COMMIT_STATE_READY_TO_COMMIT,
+    COMMIT_STATE_WAITING_FOR_ACTIVATION,
     COMMIT_STATE_WAITING_FOR_FIRST_DRAW,
     COMMIT_STATE_WAITING_FOR_FIRST_FORCED_DRAW,
   };
@@ -80,9 +88,10 @@ class CC_EXPORT SchedulerStateMachine {
   // Indicates that the system has entered and left a BeginFrame callback.
   // The scheduler will not draw more than once in a given BeginFrame
   // callback.
-  void DidEnterBeginFrame(const BeginFrameArgs& args);
-  void DidLeaveBeginFrame();
-  bool inside_begin_frame() const { return inside_begin_frame_; }
+  void OnBeginFrame(const BeginFrameArgs& args);
+  void OnBeginFrameDeadline();
+  bool ShouldTriggerBeginFrameDeadlineEarly() const;
+  bool InsideBeginFrame() const;
 
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool visible);
@@ -161,13 +170,17 @@ class CC_EXPORT SchedulerStateMachine {
  protected:
   bool ShouldDrawForced() const;
   bool ScheduledToDraw() const;
+  bool WillDrawNewTree() const;
   bool ShouldDraw() const;
+  bool ShouldDrawInternal(BeginFrameState begin_frame_state) const;
   bool ShouldAttemptTreeActivation() const;
   bool ShouldAcquireLayerTexturesForMainThread() const;
   bool ShouldCheckForCompletedTileUploads() const;
+  bool ShouldSendBeginFrameToMainThread() const;
   bool HasDrawnThisFrame() const;
-  bool HasAttemptedTreeActivationThisFrame() const;
-  bool HasCheckedForCompletedTileUploadsThisFrame() const;
+  bool HasAttemptedTreeActivationThisFrameAttempt() const;
+  bool HasCheckedForCompletedTileUploadsThisFrameAttempt() const;
+  bool HasSentBeginFrameToMainThreadThisFrame() const;
 
   const SchedulerSettings settings_;
 
@@ -175,9 +188,11 @@ class CC_EXPORT SchedulerStateMachine {
   int commit_count_;
 
   int current_frame_number_;
-  int last_frame_number_where_draw_was_called_;
-  int last_frame_number_where_tree_activation_attempted_;
-  int last_frame_number_where_check_for_completed_tile_uploads_called_;
+  int current_frame_attempt_;
+  int last_frame_number_draw_was_called_;
+  int last_frame_number_begin_frame_sent_to_main_thread_;
+  int last_frame_attempt_tree_activation_attempted_;
+  int last_frame_attempt_check_for_completed_tile_uploads_called_;
   int consecutive_failed_draws_;
   int maximum_number_of_failed_draws_before_draw_is_forced_;
   bool needs_redraw_;
@@ -188,7 +203,9 @@ class CC_EXPORT SchedulerStateMachine {
   bool needs_forced_commit_;
   bool expect_immediate_begin_frame_for_main_thread_;
   bool main_thread_needs_layer_textures_;
-  bool inside_begin_frame_;
+  BeginFrameState begin_frame_state_;
+  bool commit_tree_has_been_drawn_or_null_;
+  bool active_tree_has_been_drawn_or_null_;
   BeginFrameArgs last_begin_frame_args_;
   bool visible_;
   bool can_start_;