cc: Allow the main thread to cancel commits

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 61 matching lines @@
   Action NextAction() const;
   void UpdateState(Action action);
 
   // Indicates whether the main thread needs a begin frame callback in order to
   // make progress.
   bool BeginFrameNeededToDrawByImplThread() const;
   bool ProactiveBeginFrameWantedByImplThread() const;
 
   // Indicates that the system has entered and left a BeginFrame callback.
   // The scheduler will not draw more than once in a given BeginFrame
-  // callback.
+  // callback nor send more than one BeginFrame message.
   void DidEnterBeginFrame(const BeginFrameArgs& args);
   void DidLeaveBeginFrame();
   bool inside_begin_frame() const { return inside_begin_frame_; }
 
   // Indicates whether the LayerTreeHostImpl is visible.
   void SetVisible(bool visible);
 
   // Indicates that a redraw is required, either due to the impl tree changing
   // or the screen being damaged and simply needing redisplay.
   void SetNeedsRedraw();
@@ skipping 20 matching lines @@
   // begin frame to finish.
   void SetNeedsForcedCommit();
 
   // Call this only in response to receiving an
   // ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD from NextAction.
   // Indicates that all painting is complete.
   void FinishCommit();
 
   // Call this only in response to receiving an
   // ACTION_SEND_BEGIN_FRAME_TO_MAIN_THREAD from NextAction if the client
-  // rejects the begin frame message.
-  void BeginFrameAbortedByMainThread();
+  // rejects the begin frame message.  If did_handle is false, then
+  // another commit will be retried soon.
+  void BeginFrameAbortedByMainThread(bool did_handle);
 
   // Request exclusive access to the textures that back single buffered
   // layers on behalf of the main thread. Upon acquisition,
   // ACTION_DRAW_IF_POSSIBLE will not draw until the main thread releases the
   // textures to the impl thread by committing the layers.
   void SetMainThreadNeedsLayerTextures();
 
   // Set that we can create the first OutputSurface and start the scheduler.
   void SetCanStart() { can_start_ = true; }
 
@@ skipping 33 matching lines @@
   bool HasDrawnThisFrame() const;
   bool HasAttemptedTreeActivationThisFrame() const;
   bool HasCheckedForCompletedTileUploadsThisFrame() const;
 
   const SchedulerSettings settings_;
 
   CommitState commit_state_;
   int commit_count_;
 
   int current_frame_number_;
+  int last_frame_number_where_begin_frame_sent_to_main_thread_;
   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 consecutive_failed_draws_;
   int maximum_number_of_failed_draws_before_draw_is_forced_;
   bool needs_redraw_;
   bool swap_used_incomplete_tile_;
   bool needs_forced_redraw_;
   bool needs_forced_redraw_after_next_commit_;
   bool needs_commit_;
@@ skipping 11 matching lines @@
   OutputSurfaceState output_surface_state_;
   bool did_create_and_initialize_first_output_surface_;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(SchedulerStateMachine);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_STATE_MACHINE_H_