Refactoring the way begin frame sources inside scheduler work.

cc/scheduler/delay_based_time_source.h

 // 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.
 
 #ifndef CC_SCHEDULER_DELAY_BASED_TIME_SOURCE_H_
 #define CC_SCHEDULER_DELAY_BASED_TIME_SOURCE_H_
 
 #include <string>
 
 #include "base/memory/weak_ptr.h"
@@ skipping 24 matching lines @@
     : public base::RefCounted<DelayBasedTimeSource> {
  public:
   static scoped_refptr<DelayBasedTimeSource> Create(
       base::TimeDelta interval, base::SingleThreadTaskRunner* task_runner);
 
   virtual void SetClient(TimeSourceClient* client);
 
   // TimeSource implementation
   virtual void SetTimebaseAndInterval(base::TimeTicks timebase,
                                       base::TimeDelta interval);
+  base::TimeDelta Interval() const { return next_parameters_.interval; }
 
   virtual base::TimeTicks SetActive(bool active);
   virtual bool Active() const;
 
   // Get the last and next tick times. NextTickTime() returns null when
   // inactive.
   virtual base::TimeTicks LastTickTime() const;
   virtual base::TimeTicks NextTickTime() const;
 
   // Virtual for testing.
@@ skipping 54 matching lines @@
 
   virtual std::string TypeString() const OVERRIDE;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(DelayBasedTimeSourceHighRes);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_DELAY_BASED_TIME_SOURCE_H_