2 files changed, 15 insertions, 3 deletions
diff --git a/cc/scheduler/frame_rate_controller.cc b/cc/scheduler/frame_rate_controller.cc
index 811892d..c2294ea 100644
--- a/cc/scheduler/frame_rate_controller.cc
+++ b/cc/scheduler/frame_rate_controller.cc
@@ -65,10 +65,11 @@ FrameRateController::~FrameRateController() {
     time_source_->SetActive(false);
 }
 
-void FrameRateController::SetActive(bool active) {
+BeginFrameArgs FrameRateController::SetActive(bool active) {
   if (active_ == active)
-    return;
+    return BeginFrameArgs();
   TRACE_EVENT1("cc", "FrameRateController::SetActive", "active", active);
+  bool just_activated = active && !active_;
   active_ = active;
 
   if (is_time_source_throttling_) {
@@ -79,6 +80,14 @@ void FrameRateController::SetActive(bool active) {
     else
       weak_factory_.InvalidateWeakPtrs();
   }
+
+  if (just_activated) {
+    // TODO(brianderson): Use an adaptive parent compositor deadline.
+    base::TimeTicks frame_time = NextTickTime() - interval_;
+    base::TimeTicks deadline = NextTickTime();
+    return BeginFrameArgs::Create(frame_time, deadline, interval_);
+  }
+  return BeginFrameArgs();
 }
 
 void FrameRateController::SetMaxSwapsPending(int max_swaps_pending) {
diff --git a/cc/scheduler/frame_rate_controller.h b/cc/scheduler/frame_rate_controller.h
index 32e757b..0cfca0f 100644
--- a/cc/scheduler/frame_rate_controller.h
+++ b/cc/scheduler/frame_rate_controller.h
@@ -42,7 +42,10 @@ class CC_EXPORT FrameRateController {
 
   void SetClient(FrameRateControllerClient* client) { client_ = client; }
 
-  void SetActive(bool active);
+  // Returns a valid BeginFrame on activation to potentially be used
+  // retroactively.
+  BeginFrameArgs SetActive(bool active);
+
   bool IsActive() { return active_; }
 
   // Use the following methods to adjust target frame rate.