cc: Throttle swaps in Scheduler instead of OutputSurface

cc/scheduler/frame_rate_controller.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/frame_rate_controller.h"
 
 #include "base/bind.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/single_thread_task_runner.h"
 #include "cc/scheduler/delay_based_time_source.h"
 #include "cc/scheduler/time_source.h"
 #include "ui/gfx/frame_time.h"
 
 namespace cc {
 
-class FrameRateControllerTimeSourceAdapter : public TimeSourceClient {
- public:
-  static scoped_ptr<FrameRateControllerTimeSourceAdapter> Create(
-      FrameRateController* frame_rate_controller) {
-    return make_scoped_ptr(
-        new FrameRateControllerTimeSourceAdapter(frame_rate_controller));
-  }
-  virtual ~FrameRateControllerTimeSourceAdapter() {}
-
-  virtual void OnTimerTick() OVERRIDE {
-    frame_rate_controller_->OnTimerTick();
-  }
-
- private:
-  explicit FrameRateControllerTimeSourceAdapter(
-      FrameRateController* frame_rate_controller)
-      : frame_rate_controller_(frame_rate_controller) {}
-
-  FrameRateController* frame_rate_controller_;
-};
-
 FrameRateController::FrameRateController(scoped_refptr<TimeSource> timer)
     : client_(NULL),
-      num_frames_pending_(0),
-      max_swaps_pending_(0),
       interval_(BeginFrameArgs::DefaultInterval()),
       time_source_(timer),
-      active_(false),
-      is_time_source_throttling_(true),
-      manual_tick_pending_(false),
-      task_runner_(NULL),
-      weak_factory_(this) {
-  time_source_client_adapter_ =
-      FrameRateControllerTimeSourceAdapter::Create(this);
-  time_source_->SetClient(time_source_client_adapter_.get());
+      active_(false) {
+  time_source_->SetClient(this);
 }
 
-FrameRateController::FrameRateController(
-    base::SingleThreadTaskRunner* task_runner)
-    : client_(NULL),
-      num_frames_pending_(0),
-      max_swaps_pending_(0),
-      interval_(BeginFrameArgs::DefaultInterval()),
-      active_(false),
-      is_time_source_throttling_(false),
-      manual_tick_pending_(false),
-      task_runner_(task_runner),
-      weak_factory_(this) {}
-
-FrameRateController::~FrameRateController() {
-  if (is_time_source_throttling_)
-    time_source_->SetActive(false);
-}
+FrameRateController::~FrameRateController() { time_source_->SetActive(false); }
 
 BeginFrameArgs FrameRateController::SetActive(bool active) {
   if (active_ == active)
     return BeginFrameArgs();
   TRACE_EVENT1("cc", "FrameRateController::SetActive", "active", active);
   active_ = active;
 
-  if (is_time_source_throttling_) {
-    base::TimeTicks missed_tick_time = time_source_->SetActive(active);
-    if (!missed_tick_time.is_null()) {
-      base::TimeTicks deadline = NextTickTime();
-      return  BeginFrameArgs::Create(
-          missed_tick_time, deadline + deadline_adjustment_, interval_);
-    }
-  } else {
-    if (active) {
-      PostManualTick();
-    } else {
-      weak_factory_.InvalidateWeakPtrs();
-      manual_tick_pending_ = false;
-    }
+  base::TimeTicks missed_tick_time = time_source_->SetActive(active);
+  if (!missed_tick_time.is_null()) {
+    base::TimeTicks deadline = NextTickTime();
+    return BeginFrameArgs::Create(
+        missed_tick_time, deadline + deadline_adjustment_, interval_);
   }
 
   return BeginFrameArgs();
 }
 
-void FrameRateController::SetMaxSwapsPending(int max_swaps_pending) {
-  DCHECK_GE(max_swaps_pending, 0);
-  max_swaps_pending_ = max_swaps_pending;
-}
-
 void FrameRateController::SetTimebaseAndInterval(base::TimeTicks timebase,
                                                  base::TimeDelta interval) {
   interval_ = interval;
-  if (is_time_source_throttling_)
-    time_source_->SetTimebaseAndInterval(timebase, interval);
+  time_source_->SetTimebaseAndInterval(timebase, interval);
 }
 
 void FrameRateController::SetDeadlineAdjustment(base::TimeDelta delta) {
   deadline_adjustment_ = delta;
 }
 
 void FrameRateController::OnTimerTick() {
   TRACE_EVENT0("cc", "FrameRateController::OnTimerTick");
   DCHECK(active_);
 
-  // Check if we have too many frames in flight.
-  bool throttled =
-      max_swaps_pending_ && num_frames_pending_ >= max_swaps_pending_;
-  TRACE_COUNTER_ID1("cc", "ThrottledCompositor", task_runner_, throttled);
-
   if (client_) {
     // TODO(brianderson): Use an adaptive parent compositor deadline.
     base::TimeTicks frame_time = LastTickTime();
     base::TimeTicks deadline = NextTickTime();
     BeginFrameArgs args = BeginFrameArgs::Create(
         frame_time, deadline + deadline_adjustment_, interval_);
-    client_->FrameRateControllerTick(throttled, args);
-  }
-
-  if (!is_time_source_throttling_ && !throttled)
-    PostManualTick();
-}
-
-void FrameRateController::PostManualTick() {
-  if (active_ && !manual_tick_pending_) {
-    manual_tick_pending_ = true;
-    task_runner_->PostTask(FROM_HERE,
-                           base::Bind(&FrameRateController::ManualTick,
-                                      weak_factory_.GetWeakPtr()));
+    client_->FrameRateControllerTick(args);
   }
 }
 
-void FrameRateController::ManualTick() {
-  manual_tick_pending_ = false;
-  OnTimerTick();
-}
-
-void FrameRateController::DidSwapBuffers() {
-  num_frames_pending_++;
-}
-
-void FrameRateController::DidSwapBuffersComplete() {
-  DCHECK_GT(num_frames_pending_, 0);
-  num_frames_pending_--;
-  if (!is_time_source_throttling_)
-    PostManualTick();
-}
-
-void FrameRateController::DidAbortAllPendingFrames() {
-  num_frames_pending_ = 0;
-}
-
 base::TimeTicks FrameRateController::NextTickTime() {
-  if (is_time_source_throttling_)
-    return time_source_->NextTickTime();
-
-  return base::TimeTicks();
+  return time_source_->NextTickTime();
 }
 
 base::TimeTicks FrameRateController::LastTickTime() {
-  if (is_time_source_throttling_)
-    return time_source_->LastTickTime();
-
-  return gfx::FrameTime::Now();
+  return time_source_->LastTickTime();
 }
 
 }  // namespace cc