Implement Main Thread RAF Aligned Input

content/renderer/input/main_thread_event_queue.h

Index: content/renderer/input/main_thread_event_queue.h
diff --git a/content/renderer/input/main_thread_event_queue.h b/content/renderer/input/main_thread_event_queue.h
index 3e9ab9c94b8989aecb31b56643b4e8b9d92cc222..b4c5728bc8213eb745bf8ebe488dbdd53145ccbb 100644
--- a/content/renderer/input/main_thread_event_queue.h
+++ b/content/renderer/input/main_thread_event_queue.h
@@ -30,17 +30,23 @@ class EventWithDispatchType : public ScopedWebInputEventWithLatencyInfo {
       WARN_UNUSED_RESULT;
   void CoalesceWith(const EventWithDispatchType& other);
 
-  const std::deque<uint32_t>& eventsToAck() const { return eventsToAck_; }
+  const std::deque<uint32_t>& coalescedEventIds() const {
+    return coalesced_event_ids_;
+  }
   InputEventDispatchType dispatchType() const { return dispatch_type_; }
+  base::TimeTicks creationTimestamp() const { return creation_timestamp_; }
+  base::TimeTicks coalescedTimestamp() const { return coalesced_timestamp_; }
 
  private:
   InputEventDispatchType dispatch_type_;
 
-  // |eventsToAck_| contains the unique touch event id to be acked. If
+  // |coalesced_event_ids_| contains the unique touch event id to be acked. If

[tdresser, 2016/08/24 13:43:00]

event id -> event ids

[dtapuska, 2016/08/24 17:10:06]

done.

   // the events are TouchEvents the value will be 0. More importantly for

[tdresser, 2016/08/24 13:43:00]

Is this comment correct? Should it be "If the events areN'T TouchEvents?"

[dtapuska, 2016/08/24 17:10:06]

done.

   // those cases the deque ends up containing how many additional ACKs
   // need to be sent.
-  std::deque<uint32_t> eventsToAck_;
+  std::deque<uint32_t> coalesced_event_ids_;
+  base::TimeTicks creation_timestamp_;
+  base::TimeTicks coalesced_timestamp_;

[tdresser, 2016/08/24 13:43:00]

Maybe:
last_coalesced_timestamp_
or
most_recent_coalesced_timestamp_
?

[dtapuska, 2016/08/24 17:10:06]

done

 };
 
 class CONTENT_EXPORT MainThreadEventQueueClient {
@@ -58,6 +64,7 @@ class CONTENT_EXPORT MainThreadEventQueueClient {
                                  blink::WebInputEvent::Type type,
                                  InputEventAckState ack_result,
                                  uint32_t touch_event_id) = 0;
+  virtual void NeedsMainFrame(int routing_id) = 0;
 };
 
 // MainThreadEventQueue implements a queue for events that need to be
@@ -103,7 +110,8 @@ class CONTENT_EXPORT MainThreadEventQueue
       int routing_id,
       MainThreadEventQueueClient* client,
       const scoped_refptr<base::SingleThreadTaskRunner>& main_task_runner,
-      blink::scheduler::RendererScheduler* renderer_scheduler);
+      blink::scheduler::RendererScheduler* renderer_scheduler,
+      bool handle_raf_aligned_input);
 
   // Called once the compositor has handled |event| and indicated that it is
   // a non-blocking event to be queued to the main thread.
@@ -111,6 +119,7 @@ class CONTENT_EXPORT MainThreadEventQueue
                    const ui::LatencyInfo& latency,
                    InputEventDispatchType dispatch_type,
                    InputEventAckState ack_result);
+  void DispatchRafAlignedInput();
 
   // Call once the main thread has handled an outstanding |type| event
   // in flight.
@@ -124,7 +133,10 @@ class CONTENT_EXPORT MainThreadEventQueue
   ~MainThreadEventQueue();
   void QueueEvent(std::unique_ptr<EventWithDispatchType> event);
   void SendEventNotificationToMainThread();
-  void PopEventOnMainThread();
+  void DispatchSingleEvent();
+  void DispatchInFlightEvent();
+  void PossiblyScheduleMainFrame();
+
   void SendEventToMainThread(const blink::WebInputEvent* event,
                              const ui::LatencyInfo& latency,
                              InputEventDispatchType original_dispatch_type);
@@ -137,6 +149,8 @@ class CONTENT_EXPORT MainThreadEventQueue
   bool is_flinging_;
   bool last_touch_start_forced_nonblocking_due_to_fling_;
   bool enable_fling_passive_listener_flag_;
+  bool handle_raf_aligned_input_;
+  bool sent_main_frame_request_;

[tdresser, 2016/08/24 13:42:59]

We should indicate which members should only be accessed through the
event_queue_lock_.

It might even be worth bundling them into a struct, though if it's only two
members, it's probably be fine.

[dtapuska, 2016/08/24 17:10:06]

done

 
   base::Lock event_queue_lock_;
   scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;