cc: Make PrepareToDraw return an enum for why it aborts

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"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "cc/base/cc_export.h"
 #include "cc/output/begin_frame_args.h"
+#include "cc/scheduler/draw_swap_readback_result.h"
 #include "cc/scheduler/scheduler_settings.h"
 
 namespace base {
 class Value;
 }
 
 namespace cc {
 
 // The SchedulerStateMachine decides how to coordinate main thread activites
 // like painting/running javascript with rendering and input activities on the
@@ skipping 148 matching lines @@
 
   // Indicates whether a redraw is required because we are currently rendering
   // with a low resolution or checkerboarded tile.
   void SetSwapUsedIncompleteTile(bool used_incomplete_tile);
 
   // Indicates whether to prioritize animation smoothness over new content
   // activation.
   void SetSmoothnessTakesPriority(bool smoothness_takes_priority);
 
   // Indicates whether ACTION_DRAW_AND_SWAP_IF_POSSIBLE drew to the screen.
-  void DidDrawIfPossibleCompleted(bool success);
+  void DidDrawIfPossibleCompleted(DrawSwapReadbackResult::DrawResult result);
 
   // Indicates that a new commit flow needs to be performed, either to pull
   // updates from the main thread to the impl, or to push deltas from the impl
   // thread to main.
   void SetNeedsCommit();
 
   // As SetNeedsCommit(), but ensures the BeginMainFrame will be sent even
   // if we are not visible.  After this call we expect to go through
   // the forced commit flow and then return to waiting for a non-forced
   // BeginMainFrame to finish.
@@ skipping 86 matching lines @@
   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_;
 
   // 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_;
+  int consecutive_checkerboard_animations_;
   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_