Add BeginFrameObserverProxy

content/browser/compositor/delegated_frame_host.cc

Index: content/browser/compositor/delegated_frame_host.cc
diff --git a/content/browser/compositor/delegated_frame_host.cc b/content/browser/compositor/delegated_frame_host.cc
index e6cb16150673df0c4db6cc80b28610e4154792a2..81bb1bb2cd59bf47c07a89b7e1df59ed09a894eb 100644
--- a/content/browser/compositor/delegated_frame_host.cc
+++ b/content/browser/compositor/delegated_frame_host.cc
@@ -6,6 +6,7 @@
 
 #include "base/callback_helpers.h"
 #include "base/command_line.h"
+#include "cc/output/begin_frame_args.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/output/copy_output_request.h"
@@ -17,6 +18,7 @@
 #include "content/browser/compositor/resize_lock.h"
 #include "content/browser/gpu/compositor_util.h"
 #include "content/common/gpu/client/gl_helper.h"
+#include "content/common/view_messages.h"
 #include "content/public/browser/render_widget_host_view_frame_subscriber.h"
 #include "content/public/common/content_switches.h"
 #include "media/base/video_frame.h"
@@ -55,7 +57,8 @@ void RequireCallback(cc::SurfaceManager* manager,
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHost
 
-DelegatedFrameHost::DelegatedFrameHost(DelegatedFrameHostClient* client)
+DelegatedFrameHost::DelegatedFrameHost(DelegatedFrameHostClient* client,
+                                       bool begin_frame_scheduling_enabled)
     : client_(client),
       compositor_(nullptr),
       use_surfaces_(UseSurfacesEnabled()),
@@ -64,7 +67,9 @@ DelegatedFrameHost::DelegatedFrameHost(DelegatedFrameHostClient* client)
       skipped_frames_(false),
       current_scale_factor_(1.f),
       can_lock_compositor_(YES_CAN_LOCK),
-      delegated_frame_evictor_(new DelegatedFrameEvictor(this)) {
+      delegated_frame_evictor_(new DelegatedFrameEvictor(this)),
+      begin_frame_scheduling_enabled_(begin_frame_scheduling_enabled),
+      needs_begin_frames_(false) {
   ImageTransportFactory::GetInstance()->AddObserver(this);
 }
 
@@ -829,6 +834,25 @@ void DelegatedFrameHost::CopyFromCompositingSurfaceHasResultForVideo(
                                      finished_callback);
 }
 
+void DelegatedFrameHost::OnSetNeedsBeginFrames(bool needs_begin_frames) {
+  DCHECK(begin_frame_scheduling_enabled_);
+
+ if (needs_begin_frames_ == needs_begin_frames)
+   return;
+
+  needs_begin_frames_ = needs_begin_frames;
+
+  // In some cases, BeginFrame is needed before |client_|'s window is added
+  // in the root window hierarchy.
+  if (!compositor_)
+    return;
+
+  if (needs_begin_frames)
+    StartObservingBeginFrames();
+  else
+    StopObservingBeginFrames();
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHost, ui::CompositorObserver implementation:
 
@@ -878,6 +902,8 @@ void DelegatedFrameHost::OnCompositingShuttingDown(ui::Compositor* compositor) {
   DCHECK(!compositor_);
 }
 
+///////////////////////////////////////////////////////////////////////////////
+// ui::CompositorBeginFrameObserver implementation.
 void DelegatedFrameHost::OnUpdateVSyncParameters(
     base::TimeTicks timebase,
     base::TimeDelta interval) {
@@ -887,6 +913,15 @@ void DelegatedFrameHost::OnUpdateVSyncParameters(
     client_->DelegatedFrameHostUpdateVSyncParameters(timebase, interval);
 }
 
+void DelegatedFrameHost::OnSendBeginFrame(const cc::BeginFrameArgs& args) {
+  DCHECK(begin_frame_scheduling_enabled_);
+
+  client_->DelegatedFrameHostSendBeginFrame(args);
+  last_sent_begin_frame_args_ = args;
+  vsync_timebase_ = args.frame_time;
+  vsync_interval_ = args.interval;
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHost, ImageTransportFactoryObserver implementation:
 
@@ -941,6 +976,9 @@ void DelegatedFrameHost::SetCompositor(ui::Compositor* compositor) {
   DCHECK(!vsync_manager_.get());
   vsync_manager_ = compositor_->vsync_manager();
   vsync_manager_->AddObserver(this);
+
+  if (begin_frame_scheduling_enabled_ && needs_begin_frames_)
+    StartObservingBeginFrames();
 }
 
 void DelegatedFrameHost::ResetCompositor() {
@@ -957,6 +995,10 @@ void DelegatedFrameHost::ResetCompositor() {
     vsync_manager_->RemoveObserver(this);
     vsync_manager_ = NULL;
   }
+
+  if (begin_frame_scheduling_enabled_ && needs_begin_frames_)
+    StopObservingBeginFrames();
+
   compositor_ = nullptr;
 }
 
@@ -978,6 +1020,20 @@ void DelegatedFrameHost::UnlockResources() {
   delegated_frame_evictor_->UnlockFrame();
 }
 
+void DelegatedFrameHost::StartObservingBeginFrames() {
+  DCHECK(begin_frame_scheduling_enabled_);
+  DCHECK(compositor_);
+
+  compositor_->AddBeginFrameObserver(this, last_sent_begin_frame_args_);
+}
+
+void DelegatedFrameHost::StopObservingBeginFrames() {
+  DCHECK(begin_frame_scheduling_enabled_);
+  DCHECK(compositor_);
+
+  compositor_->RemoveBeginFrameObserver(this);
+}
+
 ////////////////////////////////////////////////////////////////////////////////
 // DelegatedFrameHost, ui::LayerOwnerDelegate implementation: