cc: Limit ManageTiles calls to once per-frame on average

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 236 matching lines @@
   bool ShouldBeginOutputSurfaceCreation() const;
   bool ShouldDrawForced() const;
   bool ShouldDraw() const;
   bool ShouldActivatePendingTree() const;
   bool ShouldAcquireLayerTexturesForMainThread() const;
   bool ShouldUpdateVisibleTiles() const;
   bool ShouldSendBeginMainFrame() const;
   bool ShouldCommit() const;
   bool ShouldManageTiles() const;
 
+  void AdvanceCurrentFrameNumber();
   bool HasSentBeginMainFrameThisFrame() const;
   bool HasScheduledManageTilesThisFrame() const;
   bool HasUpdatedVisibleTilesThisFrame() const;
   bool HasSwappedThisFrame() const;
 
   void UpdateStateOnCommit(bool commit_was_aborted);
   void UpdateStateOnActivation();
   void UpdateStateOnDraw(bool did_swap);
   void UpdateStateOnManageTiles();
 
   const SchedulerSettings settings_;
 
   OutputSurfaceState output_surface_state_;
   BeginImplFrameState begin_impl_frame_state_;
   CommitState commit_state_;
   TextureState texture_state_;
   ForcedRedrawOnTimeoutState forced_redraw_state_;
   SynchronousReadbackState readback_state_;
 
   BeginFrameArgs last_begin_impl_frame_args_;
 
   int commit_count_;
   int current_frame_number_;
   int last_frame_number_swap_performed_;
   int last_frame_number_begin_main_frame_sent_;
   int last_frame_number_update_visible_tiles_was_called_;
-  int last_frame_number_manage_tiles_called_;
 
+  // manage_tiles_funnel_ is "filled" each time ManageTiles is called
+  // and "drained" on each BeginImplFrame. If the funnel gets too full,
+  // we start throttling ACTION_MANAGE_TILES such that we average one
+  // ManageTile per BeginImplFrame.
+  int manage_tiles_funnel_;
   int consecutive_failed_draws_;
   bool needs_redraw_;
   bool needs_manage_tiles_;
   bool swap_used_incomplete_tile_;
   bool needs_commit_;
   bool main_thread_needs_layer_textures_;
   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 draw_if_possible_failed_;
   bool did_create_and_initialize_first_output_surface_;
   bool smoothness_takes_priority_;
   bool skip_begin_main_frame_to_reduce_latency_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_