cc: Add debug info for unexpected SwapBuffersComplete

cc/scheduler/scheduler.cc

 // 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.
 
 #include "cc/scheduler/scheduler.h"
 
 #include <algorithm>
 
 #include "base/auto_reset.h"
 #include "base/logging.h"
@@ skipping 208 matching lines @@
   state_machine_.DidSwapBuffers();
 
   // There is no need to call ProcessScheduledActions here because
   // swapping should not trigger any new actions.
   if (!inside_process_scheduled_actions_) {
     DCHECK_EQ(state_machine_.NextAction(), SchedulerStateMachine::ACTION_NONE);
   }
 }
 
 void Scheduler::DidSwapBuffersComplete() {
+  DCHECK_GT(state_machine_.pending_swaps(), 0) << AsValue()->ToString();
   state_machine_.DidSwapBuffersComplete();
   ProcessScheduledActions();
 }
 
 void Scheduler::SetImplLatencyTakesPriority(bool impl_latency_takes_priority) {
   state_machine_.SetImplLatencyTakesPriority(impl_latency_takes_priority);
   ProcessScheduledActions();
 }
 
 void Scheduler::NotifyReadyToCommit() {
@@ skipping 526 matching lines @@
     state->EndDictionary();
   }
 
   state->BeginDictionary("scheduler_state");
   state->SetDouble("time_until_anticipated_draw_time_ms",
                    (AnticipatedDrawTime() - Now()).InMillisecondsF());
   state->SetDouble("estimated_parent_draw_time_ms",
                    estimated_parent_draw_time_.InMillisecondsF());
   state->SetBoolean("last_set_needs_begin_frame_",
                     frame_source_->NeedsBeginFrames());
-  state->SetInteger("begin_retro_frame_args_",
+  state->SetInteger("begin_retro_frame_args",
                     static_cast<int>(begin_retro_frame_args_.size()));
-  state->SetBoolean("begin_retro_frame_task_",
+  state->SetBoolean("begin_retro_frame_task",
                     !begin_retro_frame_task_.IsCancelled());
-  state->SetBoolean("begin_impl_frame_deadline_task_",
+  state->SetBoolean("begin_impl_frame_deadline_task",
                     !begin_impl_frame_deadline_task_.IsCancelled());
-  state->SetBoolean("advance_commit_state_task_",
+  state->SetBoolean("advance_commit_state_task",
                     !advance_commit_state_task_.IsCancelled());
+  state->SetString("inside_action",
+                   SchedulerStateMachine::ActionToString(inside_action_));
   state->BeginDictionary("begin_impl_frame_args");
   begin_impl_frame_tracker_.AsValueInto(Now(), state);
   state->EndDictionary();
   state->EndDictionary();
 
   state->BeginDictionary("client_state");
   state->SetDouble("draw_duration_estimate_ms",
                    client_->DrawDurationEstimate().InMillisecondsF());
   state->SetDouble(
       "begin_main_frame_to_commit_duration_estimate_ms",
@@ skipping 24 matching lines @@
 }
 
 bool Scheduler::IsBeginMainFrameSentOrStarted() const {
   return (state_machine_.commit_state() ==
               SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_SENT ||
           state_machine_.commit_state() ==
               SchedulerStateMachine::COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED);
 }
 
 }  // namespace cc