Make event-targeting asynchronous in window server.

services/ui/ws/event_dispatcher.h

Index: services/ui/ws/event_dispatcher.h
diff --git a/services/ui/ws/event_dispatcher.h b/services/ui/ws/event_dispatcher.h
index 193786bd6ee5d119c42684623986a3ce9c612e94..5bcbbbae661fcd9b398eb0637c9a2ccb6e6c20f0 100644
--- a/services/ui/ws/event_dispatcher.h
+++ b/services/ui/ws/event_dispatcher.h
@@ -59,6 +59,8 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
   // any events to the delegate.
   void Reset();
 
+  const EventTargeter* event_targeter() const { return event_targeter_.get(); }
+
   void SetMousePointerDisplayLocation(const gfx::Point& display_location,
                                       const int64_t display_id);
   const gfx::Point& mouse_pointer_last_location() const {
@@ -144,6 +146,8 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
   // ANY and there is a matching accelerator with PRE_TARGET found, than only
   // OnAccelerator() is called. The expectation is after the PRE_TARGET has been
   // handled this is again called with an AcceleratorMatchPhase of POST_ONLY.
+  // This may be asynchronous if we need to find the target window for |event|
+  // asynchronously.
   void ProcessEvent(const ui::Event& event,
                     const int64_t display_id,
                     AcceleratorMatchPhase match_phase);
@@ -153,6 +157,17 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
 
   void SetMouseCursorSourceWindow(ServerWindow* window);
 
+  // Called after we found the target for the current mouse cursor to see if
+  // |mouse_pointer_last_location_| and |mouse_pointer_display_id_| need to be
+  // updated based on the new target we found. No need to call delegate's
+  // OnMouseCursorLocationChanged since mouse location would still be the same

[sky, 2017/05/31 23:36:34]

'would still be' -> is

[riajiang, 2017/06/01 18:22:12]

Done.

+  // in screen-coord.
+  // TODO(riajiang): No need to update mouse location after ozone drm can tell
+  // us the right display the cursor is on for drag-n-drop events.
+  // crbug.com/726470
+  void UpdateMousePointerLocation(const gfx::Point& new_mouse_location,
+                                  const int64_t new_mouse_display_id);
+
   void ProcessKeyEvent(const ui::KeyEvent& event,
                        AcceleratorMatchPhase match_phase);
 
@@ -170,6 +185,12 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
   // This also generates exit events as appropriate. For example, if the mouse
   // moves between one window to another an exit is generated on the first.
   void ProcessPointerEvent(const ui::PointerEvent& event);
+  void ProcessPointerEventOnFoundTarget(
+      const ui::PointerEvent& event,
+      const PointerTarget& pointer_target_found,
+      const DeepestWindow& deepest_window,
+      const gfx::Point& new_location,

[sky, 2017/05/31 23:36:34]

Please document what the args are.
optional: rename new_location to location_in_display and new_display_id to
display_id.

This comment applies to all new functions.

[riajiang, 2017/06/01 18:22:12]

Done. And renamed.

+      const int64_t new_display_id);
 
   // Adds |pointer_target| to |pointer_targets_|.
   void StartTrackingPointer(int32_t pointer_id,
@@ -182,7 +203,21 @@ class EventDispatcher : public ServerWindowObserver, public DragCursorUpdater {
   // pointer sends the appropriate event to the delegate and updates the
   // currently tracked PointerTarget appropriately.
   void UpdateTargetForPointer(int32_t pointer_id,
-                              const ui::LocatedEvent& event);
+                              const ui::PointerEvent& event,
+                              const PointerTarget& pointer_target_found);
+
+  void UpdateNonClientAreaForCurrentWindowOnFoundWindow(
+      const DeepestWindow& deepest_window,
+      const gfx::Point& new_location,
+      const int64_t new_display_id);
+  void UpdateCursorProviderByLastKnownLocationOnFoundWindow(
+      const DeepestWindow& deepest_window,
+      const gfx::Point& new_location,
+      const int64_t new_display_id);
+  void UpdateCursorProviderByLastKnownLocationWithWindow(
+      const DeepestWindow& deepest_window,
+      const gfx::Point& new_location,
+      const int64_t new_display_id);
 
   // Returns true if any pointers are in the pressed/down state.
   bool AreAnyPointersDown() const;