cc: Add debug info for unexpected SwapBuffersComplete

cc/scheduler/scheduler_state_machine.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_state_machine.h"
 
 #include "base/format_macros.h"
 #include "base/logging.h"
 #include "base/strings/stringprintf.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 16 matching lines @@
       last_frame_number_begin_main_frame_sent_(-1),
       last_frame_number_invalidate_output_surface_performed_(-1),
       animate_funnel_(false),
       request_swap_funnel_(false),
       send_begin_main_frame_funnel_(false),
       invalidate_output_surface_funnel_(false),
       prepare_tiles_funnel_(0),
       consecutive_checkerboard_animations_(0),
       max_pending_swaps_(1),
       pending_swaps_(0),
+      swaps_with_current_output_surface_(0),
       needs_redraw_(false),
       needs_animate_(false),
       needs_prepare_tiles_(false),
       needs_commit_(false),
       visible_(false),
       can_start_(false),
       can_draw_(false),
       has_pending_tree_(false),
       pending_tree_is_ready_for_activation_(false),
       active_tree_needs_first_draw_(false),
@@ skipping 163 matching lines @@
   state->SetBoolean("funnel: request_swap_funnel", request_swap_funnel_);
   state->SetBoolean("funnel: send_begin_main_frame_funnel",
                     send_begin_main_frame_funnel_);
   state->SetInteger("funnel: prepare_tiles_funnel", prepare_tiles_funnel_);
   state->SetBoolean("funnel: invalidate_output_surface_funnel",
                     invalidate_output_surface_funnel_);
   state->SetInteger("consecutive_checkerboard_animations",
                     consecutive_checkerboard_animations_);
   state->SetInteger("max_pending_swaps_", max_pending_swaps_);
   state->SetInteger("pending_swaps_", pending_swaps_);
+  state->SetInteger("swaps_with_current_output_surface",
+                    swaps_with_current_output_surface_);
   state->SetBoolean("needs_redraw", needs_redraw_);
   state->SetBoolean("needs_animate_", needs_animate_);
   state->SetBoolean("needs_prepare_tiles", needs_prepare_tiles_);
   state->SetBoolean("needs_commit", needs_commit_);
   state->SetBoolean("visible", visible_);
   state->SetBoolean("can_start", can_start_);
   state->SetBoolean("can_draw", can_draw_);
   state->SetBoolean("has_pending_tree", has_pending_tree_);
   state->SetBoolean("pending_tree_is_ready_for_activation",
                     pending_tree_is_ready_for_activation_);
@@ skipping 782 matching lines @@
     needs_prepare_tiles_ = true;
   }
 }
 
 void SchedulerStateMachine::SetMaxSwapsPending(int max) {
   max_pending_swaps_ = max;
 }
 
 void SchedulerStateMachine::DidSwapBuffers() {
   pending_swaps_++;
+  swaps_with_current_output_surface_++;
+
   DCHECK_LE(pending_swaps_, max_pending_swaps_);
 
   did_perform_swap_in_last_draw_ = true;
   last_frame_number_swap_performed_ = current_frame_number_;
 }
 
 void SchedulerStateMachine::DidSwapBuffersComplete() {
-  DCHECK_GT(pending_swaps_, 0);
   pending_swaps_--;
 }
 
 void SchedulerStateMachine::SetImplLatencyTakesPriority(
     bool impl_latency_takes_priority) {
   impl_latency_takes_priority_ = impl_latency_takes_priority;
 }
 
 void SchedulerStateMachine::DidDrawIfPossibleCompleted(DrawResult result) {
   switch (result) {
@@ skipping 97 matching lines @@
   DCHECK_EQ(output_surface_state_, OUTPUT_SURFACE_CREATING);
   output_surface_state_ = OUTPUT_SURFACE_WAITING_FOR_FIRST_COMMIT;
 
   if (did_create_and_initialize_first_output_surface_) {
     // TODO(boliu): See if we can remove this when impl-side painting is always
     // on. Does anything on the main thread need to update after recreate?
     needs_commit_ = true;
   }
   did_create_and_initialize_first_output_surface_ = true;
   pending_swaps_ = 0;
+  swaps_with_current_output_surface_ = 0;
 }
 
 void SchedulerStateMachine::NotifyBeginMainFrameStarted() {
   DCHECK_EQ(commit_state_, COMMIT_STATE_BEGIN_MAIN_FRAME_SENT);
   commit_state_ = COMMIT_STATE_BEGIN_MAIN_FRAME_STARTED;
 }
 
 bool SchedulerStateMachine::HasInitializedOutputSurface() const {
   switch (output_surface_state_) {
     case OUTPUT_SURFACE_LOST:
@@ skipping 16 matching lines @@
       static_cast<int>(begin_impl_frame_state_),
       static_cast<int>(commit_state_),
       has_pending_tree_ ? 'T' : 'F',
       pending_tree_is_ready_for_activation_ ? 'T' : 'F',
       active_tree_needs_first_draw_ ? 'T' : 'F',
       max_pending_swaps_,
       pending_swaps_);
 }
 
 }  // namespace cc