cc: Send all begin frames using a PostTask.

cc/scheduler/delay_based_time_source.cc

Index: cc/scheduler/delay_based_time_source.cc
diff --git a/cc/scheduler/delay_based_time_source.cc b/cc/scheduler/delay_based_time_source.cc
index bc2ec5f8744971904b4e21a5da611c2dded424ec..7a59fe70fa6566be6ae9df52bb956ce32cb731ae 100644
--- a/cc/scheduler/delay_based_time_source.cc
+++ b/cc/scheduler/delay_based_time_source.cc
@@ -21,14 +21,16 @@ namespace cc {
 // The following methods correspond to the DelayBasedTimeSource that uses
 // the base::TimeTicks::Now as the timebase.
 DelayBasedTimeSource::DelayBasedTimeSource(
-    base::SingleThreadTaskRunner* task_runner)
-    : client_(nullptr),
+    base::SingleThreadTaskRunner* task_runner,
+    base::TickClock* clock)
+    : task_runner_(task_runner),
+      clock_(clock),
+      client_(nullptr),
       active_(false),
       timebase_(base::TimeTicks()),
       interval_(BeginFrameArgs::DefaultInterval()),
       last_tick_time_(base::TimeTicks() - interval_),
       next_tick_time_(base::TimeTicks()),
-      task_runner_(task_runner),
       weak_factory_(this) {}
 
 DelayBasedTimeSource::~DelayBasedTimeSource() {}
@@ -54,7 +56,13 @@ base::TimeDelta DelayBasedTimeSource::Interval() const {
   return interval_;
 }
 
-bool DelayBasedTimeSource::Active() const { return active_; }
+base::TimeTicks DelayBasedTimeSource::Now() {
+  return clock_ ? clock_->NowTicks() : base::TimeTicks::Now();

[brianderson, 2016/07/13 21:14:49]

DefaultTickClock?

+}
+
+bool DelayBasedTimeSource::Active() const {
+  return active_;
+}
 
 base::TimeTicks DelayBasedTimeSource::LastTickTime() const {
   return last_tick_time_;
@@ -86,10 +94,6 @@ void DelayBasedTimeSource::SetTimebaseAndInterval(base::TimeTicks timebase,
   timebase_ = timebase;
 }
 
-base::TimeTicks DelayBasedTimeSource::Now() const {
-  return base::TimeTicks::Now();
-}
-
 // This code tries to achieve an average tick rate as close to interval_ as
 // possible.  To do this, it has to deal with a few basic issues:
 //   1. PostDelayedTask can delay only at a millisecond granularity. So, 16.666
@@ -159,13 +163,8 @@ void DelayBasedTimeSource::PostNextTickTask(base::TimeTicks now) {
                                 next_tick_time_ - now);
 }
 
-std::string DelayBasedTimeSource::TypeString() const {
-  return "DelayBasedTimeSource";
-}
-
 void DelayBasedTimeSource::AsValueInto(
     base::trace_event::TracedValue* state) const {
-  state->SetString("type", TypeString());
   state->SetDouble("last_tick_time_us", LastTickTime().ToInternalValue());
   state->SetDouble("next_tick_time_us", NextTickTime().ToInternalValue());
   state->SetDouble("interval_us", interval_.InMicroseconds());