Remove "mixin" from BeginFrameSource/Observer base classes.

cc/scheduler/scheduler.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_SCHEDULER_H_
 #define CC_SCHEDULER_SCHEDULER_H_
 
 #include <deque>
 #include <string>
 
@@ skipping 55 matching lines @@
   virtual BeginFrameSource* ConstructPrimaryFrameSource(Scheduler* scheduler);
   virtual BeginFrameSource* ConstructUnthrottledFrameSource(
       Scheduler* scheduler);
 
  protected:
   SchedulerFrameSourcesConstructor() {}
 
   friend class Scheduler;
 };
 
-class CC_EXPORT Scheduler : public BeginFrameObserverMixIn {
+class CC_EXPORT Scheduler : public BeginFrameObserverBase {
  public:
   static scoped_ptr<Scheduler> Create(
       SchedulerClient* client,
       const SchedulerSettings& scheduler_settings,
       int layer_tree_host_id,
       const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
       scoped_ptr<BeginFrameSource> external_begin_frame_source) {
     SchedulerFrameSourcesConstructor frame_sources_constructor;
     return make_scoped_ptr(new Scheduler(client,
                                          scheduler_settings,
                                          layer_tree_host_id,
                                          task_runner,
                                          external_begin_frame_source.Pass(),
                                          &frame_sources_constructor));
   }
 
   ~Scheduler() override;
 
-  // BeginFrameObserverMixin
-  bool OnBeginFrameMixInDelegate(const BeginFrameArgs& args) override;
+  // BeginFrameObserverBase
+  bool OnBeginFrameDerivedImpl(const BeginFrameArgs& args) override;
 
   void OnDrawForOutputSurface();
 
   const SchedulerSettings& settings() const { return settings_; }
 
   void CommitVSyncParameters(base::TimeTicks timebase,
                              base::TimeDelta interval);
   void SetEstimatedParentDrawTime(base::TimeDelta draw_time);
 
   void SetCanStart();
@@ skipping 146 matching lines @@
 
   friend class SchedulerFrameSourcesConstructor;
   friend class TestSchedulerFrameSourcesConstructor;
 
   DISALLOW_COPY_AND_ASSIGN(Scheduler);
 };
 
 }  // namespace cc
 
 #endif  // CC_SCHEDULER_SCHEDULER_H_