cc: Make BackToBackBeginFrameSource a SyntheticBeginFrameSource.

cc/trees/proxy_impl.cc

 // Copyright 2015 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/trees/proxy_impl.h"
 
 #include <algorithm>
 #include <string>
 
 #include "base/auto_reset.h"
 #include "base/memory/ptr_util.h"
 #include "base/trace_event/trace_event.h"
 #include "base/trace_event/trace_event_argument.h"
 #include "base/trace_event/trace_event_synthetic_delay.h"
 #include "cc/animation/animation_events.h"
 #include "cc/debug/benchmark_instrumentation.h"
 #include "cc/debug/devtools_instrumentation.h"
 #include "cc/input/top_controls_manager.h"
 #include "cc/output/context_provider.h"
 #include "cc/output/output_surface.h"
 #include "cc/scheduler/compositor_timing_history.h"
+#include "cc/scheduler/delay_based_time_source.h"
 #include "cc/trees/layer_tree_host.h"
 #include "cc/trees/layer_tree_impl.h"
 #include "cc/trees/task_runner_provider.h"
 #include "gpu/command_buffer/client/gles2_interface.h"
 
 namespace cc {
 
 namespace {
 
 // Measured in seconds.
@@ skipping 51 matching lines @@
           rendering_stats_instrumentation_));
 
   BeginFrameSource* frame_source = external_begin_frame_source_.get();
   if (!scheduler_settings.throttle_frame_production) {
     // Unthrottled source takes precedence over external sources.
     unthrottled_begin_frame_source_.reset(new BackToBackBeginFrameSource(
         task_runner_provider_->ImplThreadTaskRunner()));
     frame_source = unthrottled_begin_frame_source_.get();
   }
   if (!frame_source) {
-    synthetic_begin_frame_source_.reset(new SyntheticBeginFrameSource(
-        task_runner_provider_->ImplThreadTaskRunner(),
-        BeginFrameArgs::DefaultInterval()));
+    synthetic_begin_frame_source_.reset(
+        new SyntheticBeginFrameSource(base::MakeUnique<DelayBasedTimeSource>(
+            task_runner_provider_->ImplThreadTaskRunner())));
     frame_source = synthetic_begin_frame_source_.get();
   }
   scheduler_ =
       Scheduler::Create(this, scheduler_settings, layer_tree_host_id_,
                         task_runner_provider_->ImplThreadTaskRunner(),
                         frame_source, std::move(compositor_timing_history));
 
   DCHECK_EQ(scheduler_->visible(), layer_tree_host_impl_->visible());
 }
 
@@ skipping 192 matching lines @@
 void ProxyImpl::DidLoseOutputSurfaceOnImplThread() {
   TRACE_EVENT0("cc", "ProxyImpl::DidLoseOutputSurfaceOnImplThread");
   DCHECK(IsImplThread());
   channel_impl_->DidLoseOutputSurface();
   scheduler_->DidLoseOutputSurface();
 }
 
 void ProxyImpl::CommitVSyncParameters(base::TimeTicks timebase,
                                       base::TimeDelta interval) {
   DCHECK(IsImplThread());
-  if (!synthetic_begin_frame_source_)
-    return;
-
-  if (interval.is_zero()) {
-    // TODO(brianderson): We should not be receiving 0 intervals.
-    interval = BeginFrameArgs::DefaultInterval();
-  }
-  synthetic_begin_frame_source_->OnUpdateVSyncParameters(timebase, interval);
+  if (synthetic_begin_frame_source_)
+    synthetic_begin_frame_source_->OnUpdateVSyncParameters(timebase, interval);
 }
 
 void ProxyImpl::SetBeginFrameSource(BeginFrameSource* source) {
   // During shutdown, destroying the OutputSurface may unset the
   // BeginFrameSource.
   if (scheduler_) {
     // TODO(enne): this overrides any preexisting begin frame source.  Those
     // other sources will eventually be removed and this will be the only path.
     scheduler_->SetBeginFrameSource(source);
   }
@@ skipping 359 matching lines @@
 bool ProxyImpl::IsMainThreadBlocked() const {
   return task_runner_provider_->IsMainThreadBlocked();
 }
 
 ProxyImpl::BlockedMainCommitOnly& ProxyImpl::blocked_main_commit() {
   DCHECK(IsMainThreadBlocked() && commit_completion_event_);
   return main_thread_blocked_commit_vars_unsafe_;
 }
 
 }  // namespace cc