cc: Do not use current frame number in state machine decisions.

cc/scheduler/scheduler_state_machine.h

 // Copyright 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 #define CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 264 matching lines @@
 
   bool ShouldAnimate() const;
   bool ShouldBeginOutputSurfaceCreation() const;
   bool ShouldDraw() const;
   bool ShouldActivatePendingTree() const;
   bool ShouldSendBeginMainFrame() const;
   bool ShouldCommit() const;
   bool ShouldPrepareTiles() const;
 
   void AdvanceCurrentFrameNumber();
-  bool HasAnimatedThisFrame() const;
-  bool HasSentBeginMainFrameThisFrame() const;
-  bool HasRequestedSwapThisFrame() const;
-  bool HasSwappedThisFrame() const;
 
   void UpdateStateOnCommit(bool commit_had_no_updates);
   void UpdateStateOnActivation();
   void UpdateStateOnDraw(bool did_request_swap);
   void UpdateStateOnPrepareTiles();
 
   const SchedulerSettings settings_;
 
   OutputSurfaceState output_surface_state_;
   BeginImplFrameState begin_impl_frame_state_;
   CommitState commit_state_;
   ForcedRedrawOnTimeoutState forced_redraw_state_;
 
+  // These are used for tracing only.
   int commit_count_;
   int current_frame_number_;
   int last_frame_number_animate_performed_;
   int last_frame_number_swap_performed_;
   int last_frame_number_swap_requested_;
   int last_frame_number_begin_main_frame_sent_;
 
+  // These are used to ensure that an action only happens once per frame,
+  // deadline, etc.
+  bool animate_funnel_;

[brianderson, 2015/03/19 23:31:43]

animate_funnel_ can be reset in the middle of a frame, so I see why you don't
call these animated_this_frame or something like that.

It's a little weird to call these funnels when they are bools, but I guess it
groups them conceptually with the prepare_tiles_funnel_, which is nice.

Not sure where I'm going with this. I can't come up with a better name than
funnel.

[sunnyps, 2015/03/20 01:13:44]

We can change the names later - I wasn't able to come up anything better.

+  bool perform_swap_funnel_;
+  bool request_swap_funnel_;
+  bool send_begin_main_frame_funnel_;
   // prepare_tiles_funnel_ is "filled" each time PrepareTiles is called
   // and "drained" on each BeginImplFrame. If the funnel gets too full,
   // we start throttling ACTION_PREPARE_TILES such that we average one
   // PrepareTiles per BeginImplFrame.
   int prepare_tiles_funnel_;

[brianderson, 2015/03/19 23:31:43]

nit: Space after this line to separate all the funnels from the other variables?

[sunnyps, 2015/03/20 01:13:44]

Done.

   int consecutive_checkerboard_animations_;
   int max_pending_swaps_;
   int pending_swaps_;
   bool needs_redraw_;
   bool needs_animate_;
   bool needs_prepare_tiles_;
   bool needs_commit_;
   bool inside_poll_for_anticipated_draw_triggers_;
   bool visible_;
   bool can_start_;
   bool can_draw_;
   bool has_pending_tree_;
   bool pending_tree_is_ready_for_activation_;
   bool active_tree_needs_first_draw_;
-  bool did_commit_after_animating_;
   bool did_create_and_initialize_first_output_surface_;
   bool impl_latency_takes_priority_;
   bool skip_next_begin_main_frame_to_reduce_latency_;
   bool skip_begin_main_frame_to_reduce_latency_;
   bool continuous_painting_;
   bool children_need_begin_frames_;
   bool defer_commits_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_