Unified BeginFrame scheduling

content/browser/renderer_host/display_link_mac.cc

 // 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.
 
 #include "content/browser/renderer_host/display_link_mac.h"
 
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 
 namespace base {
@@ skipping 76 matching lines @@
 
   base::AutoLock lock(lock_);
   if (!timebase_and_interval_valid_)
     return false;
 
   *timebase = timebase_;
   *interval = interval_;
   return true;
 }
 
+void DisplayLinkMac::AddObserver(Observer* observer) {
+  StartOrContinueDisplayLink();
+  observer_list_.AddObserver(observer);
+}
+
+void DisplayLinkMac::RemoveObserver(Observer* observer) {
+  observer_list.RemoveObserver(observer);
+}
+
 void DisplayLinkMac::Tick(const CVTimeStamp* cv_time) {
   TRACE_EVENT0("browser", "DisplayLinkMac::GetVSyncParameters");
   base::AutoLock lock(lock_);
 
   // Verify that videoRefreshPeriod is 32 bits.
   DCHECK((cv_time->videoRefreshPeriod & ~0xffffFFFFull) == 0ull);
 
   // Verify that the numerator and denominator make some sense.
   uint32 numerator = static_cast<uint32>(cv_time->videoRefreshPeriod);
   uint32 denominator = cv_time->videoTimeScale;
   if (numerator <= 0 || denominator <= 0) {
     LOG(WARNING) << "Unexpected numerator or denominator, bailing.";
     return;
   }
 
   timebase_ = base::TimeTicks::FromInternalValue(
       cv_time->hostTime / 1000);
   interval_ = base::TimeDelta::FromMicroseconds(
       1000000 * static_cast<int64>(numerator) / denominator);
   timebase_and_interval_valid_ = true;
+
+  FOR_EACH_OBSERVER(Observer,
+                    observer_list_,
+                    OnVSync(timebase_, interval_));
 }
 
 void DisplayLinkMac::StartOrContinueDisplayLink() {
   // Reset the timer, so that the display link won't be turned off for another
   // second.
   stop_timer_.Reset();
 
   if (CVDisplayLinkIsRunning(display_link_))
     return;
 
@@ skipping 24 matching lines @@
   display_link_mac->Tick(output_time);
   return kCVReturnSuccess;
 }
 
 // static
 base::LazyInstance<DisplayLinkMac::DisplayMap>
     DisplayLinkMac::display_map_ = LAZY_INSTANCE_INITIALIZER;
 
 }  // content