Teach main thread event queue about closures.

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 c793bdd7efcc0a2b0fc580f5095e61eb3cba3f93..45923f8fcac78f59d6461de485d1f5a4c6c7b953 100644
--- a/content/renderer/input/main_thread_event_queue.h
+++ b/content/renderer/input/main_thread_event_queue.h
@@ -10,8 +10,8 @@
 #include "content/common/content_export.h"
 #include "content/common/input/input_event_ack_state.h"
 #include "content/common/input/input_event_dispatch_type.h"
-#include "content/common/input/web_input_event_queue.h"
 #include "content/public/common/content_features.h"
+#include "content/renderer/input/main_thread_event_queue_task_list.h"
 #include "content/renderer/input/scoped_web_input_event_with_latency_info.h"
 #include "third_party/WebKit/public/platform/WebInputEvent.h"
 #include "third_party/WebKit/public/platform/scheduler/renderer/renderer_scheduler.h"
@@ -20,50 +20,6 @@
 
 namespace content {
 
-class EventWithDispatchType : public ScopedWebInputEventWithLatencyInfo {
- public:
-  EventWithDispatchType(ui::WebScopedInputEvent event,
-                        const ui::LatencyInfo& latency,
-                        InputEventDispatchType dispatch_type,
-                        bool originally_cancelable);
-  ~EventWithDispatchType();
-  void CoalesceWith(const EventWithDispatchType& other);
-
-  const std::deque<uint32_t>& blockingCoalescedEventIds() const {
-    return blocking_coalesced_event_ids_;
-  }
-  InputEventDispatchType dispatchType() const { return dispatch_type_; }
-  base::TimeTicks creationTimestamp() const { return creation_timestamp_; }
-  base::TimeTicks lastCoalescedTimestamp() const {
-    return last_coalesced_timestamp_;
-  }
-
-  size_t coalescedCount() const {
-    return non_blocking_coalesced_count_ + blocking_coalesced_event_ids_.size();
-  }
-
-  bool originallyCancelable() const { return originally_cancelable_; }
-
- private:
-  InputEventDispatchType dispatch_type_;
-
-  // Contains the unique touch event ids to be acked. If
-  // the events are not TouchEvents the values will be 0. More importantly for
-  // those cases the deque ends up containing how many additional ACKs
-  // need to be sent.
-  std::deque<uint32_t> blocking_coalesced_event_ids_;
-  // Contains the number of non-blocking events coalesced.
-  size_t non_blocking_coalesced_count_;
-  base::TimeTicks creation_timestamp_;
-  base::TimeTicks last_coalesced_timestamp_;
-
-  // Whether the received event was originally cancelable or not. The compositor
-  // input handler can change the event based on presence of event handlers so
-  // this is the state at which the renderer received the event from the
-  // browser.
-  bool originally_cancelable_;
-};
-
 class CONTENT_EXPORT MainThreadEventQueueClient {
  public:
   // Handle an |event| that was previously queued (possibly
@@ -134,6 +90,7 @@ class CONTENT_EXPORT MainThreadEventQueue
                    InputEventDispatchType dispatch_type,
                    InputEventAckState ack_result);
   void DispatchRafAlignedInput(base::TimeTicks frame_time);
+  void QueueClosure(const base::Closure& closure);
 
   // Call once the main thread has handled an outstanding |type| event
   // in flight.
@@ -144,9 +101,9 @@ class CONTENT_EXPORT MainThreadEventQueue
  private:
   friend class base::RefCountedThreadSafe<MainThreadEventQueue>;
   ~MainThreadEventQueue();
-  void QueueEvent(std::unique_ptr<EventWithDispatchType> event);
-  void SendEventNotificationToMainThread();
-  void DispatchSingleEvent();
+  void QueueEvent(std::unique_ptr<MainThreadEventQueueTask> event);
+  void PostTaskToMainThread();
+  void DispatchEvents();
   void DispatchInFlightEvent();
   void PossiblyScheduleMainFrame();
 
@@ -154,14 +111,15 @@ class CONTENT_EXPORT MainThreadEventQueue
                              const ui::LatencyInfo& latency,
                              InputEventDispatchType original_dispatch_type);
 
-  bool IsRafAlignedInputDisabled();
-  bool IsRafAlignedEvent(const blink::WebInputEvent& event);
+  bool IsRafAlignedInputDisabled() const;
+  bool IsRafAlignedEvent(
+      const std::unique_ptr<MainThreadEventQueueTask>& item) const;
 
   friend class MainThreadEventQueueTest;
   friend class MainThreadEventQueueInitializationTest;
   int routing_id_;
   MainThreadEventQueueClient* client_;
-  std::unique_ptr<EventWithDispatchType> in_flight_event_;
+  std::unique_ptr<MainThreadEventQueueTask> in_flight_event_;
   bool last_touch_start_forced_nonblocking_due_to_fling_;
   bool enable_fling_passive_listener_flag_;
   bool enable_non_blocking_due_to_main_thread_responsiveness_flag_;
@@ -174,8 +132,11 @@ class CONTENT_EXPORT MainThreadEventQueue
     SharedState();
     ~SharedState();
 
-    WebInputEventQueue<EventWithDispatchType> events_;
+    MainThreadEventQueueTaskList events_;
+    // A BeginMainFrame has been requested but not received yet.
     bool sent_main_frame_request_;
+    // A PostTask to the main thread has been sent but not executed yet.
+    bool sent_post_task_;
     base::TimeTicks last_async_touch_move_timestamp_;
   };