Unified BeginFrame scheduling

content/browser/renderer_host/display_link_mac.h

 // Copyright 2014 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 CONTENT_BROWSER_RENDERER_HOST_DISPLAY_LINK_MAC_H_
 #define CONTENT_BROWSER_RENDERER_HOST_DISPLAY_LINK_MAC_H_
 
 #include <QuartzCore/CVDisplayLink.h>
 #include <map>
 
 #include "base/lazy_instance.h"
 #include "base/mac/scoped_typeref.h"
 #include "base/memory/ref_counted.h"
+#include "base/observer_list.h"
 #include "base/synchronization/lock.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 
 namespace content {
 
 class DisplayLinkMac : public base::RefCounted<DisplayLinkMac> {
  public:
+  class Observer {
+   public:
+    virtual void OnVSync(base::TimeTicks timebase,
+                         base::TimeDelta interval) = 0;
+  };
+
   static scoped_refptr<DisplayLinkMac> GetForDisplay(
       CGDirectDisplayID display_id);
 
   // Get vsync scheduling parameters.
   bool GetVSyncParameters(
       base::TimeTicks* timebase,
       base::TimeDelta* interval);
 
+  void AddObserver(Observer* observer);
+  void RemoveObserver(Observer* observer);
+
  private:
   friend class base::RefCounted<DisplayLinkMac>;
 
   DisplayLinkMac(
       CGDirectDisplayID display_id,
       base::ScopedTypeRef<CVDisplayLinkRef> display_link);
   virtual ~DisplayLinkMac();
 
   void StartOrContinueDisplayLink();
   void StopDisplayLink();
@@ skipping 18 matching lines @@
   base::DelayTimer<DisplayLinkMac> stop_timer_;
 
   // VSync parameters computed during Tick.
   bool timebase_and_interval_valid_;
   base::TimeTicks timebase_;
   base::TimeDelta interval_;
 
   // Lock for sharing data between UI thread and display-link thread.
   base::Lock lock_;
 
+  ObserverList<Observer> observer_list_;
+
   // Each display link instance consumes a non-negligible number of cycles, so
   // make all display links on the same screen share the same object.
   typedef std::map<CGDirectDisplayID, DisplayLinkMac*> DisplayMap;
   static base::LazyInstance<DisplayMap> display_map_;
 };
 
 }  // content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_DISPLAY_LINK_MAC_H_