Keep root_location to be in pixels and display coordinates in WS.

services/ui/ws/event_dispatcher_delegate.h

Index: services/ui/ws/event_dispatcher_delegate.h
diff --git a/services/ui/ws/event_dispatcher_delegate.h b/services/ui/ws/event_dispatcher_delegate.h
index 69b7a1b40ee9d39917bf6703ce2d321111ae48c1..28a2a0a123f12e8aeb0dc4ba1796517bb9833715 100644
--- a/services/ui/ws/event_dispatcher_delegate.h
+++ b/services/ui/ws/event_dispatcher_delegate.h
@@ -31,11 +31,13 @@ class EventDispatcherDelegate {
   };
 
   virtual void OnAccelerator(uint32_t accelerator,
+                             const int64_t display_id,
                              const ui::Event& event,
                              AcceleratorPhase phase) = 0;
 
   virtual void SetFocusedWindowFromEventDispatcher(ServerWindow* window) = 0;
-  virtual ServerWindow* GetFocusedWindowForEventDispatcher() = 0;
+  virtual ServerWindow* GetFocusedWindowForEventDispatcher(
+      const int64_t display_id) = 0;
 
   // Called when capture should be set on the native display. |window| is the
   // window capture is being set on.
@@ -55,11 +57,13 @@ class EventDispatcherDelegate {
   virtual void OnCaptureChanged(ServerWindow* new_capture,
                                 ServerWindow* old_capture) = 0;
 
-  virtual void OnMouseCursorLocationChanged(const gfx::Point& point) = 0;
+  virtual void OnMouseCursorLocationChanged(const gfx::Point& point,
+                                            const int64_t display_id) = 0;
 
   // Dispatches an event to the specific client.
   virtual void DispatchInputEventToWindow(ServerWindow* target,
                                           ClientSpecificId client_id,
+                                          const int64_t display_id,
                                           const ui::Event& event,
                                           Accelerator* accelerator) = 0;
 
@@ -69,14 +73,20 @@ class EventDispatcherDelegate {
                                                   bool in_nonclient_area) = 0;
 
   // Returns the window to start searching from at the specified location, or
-  // null if there is a no window containing |location|. |location| should be in
-  // screen coordinates and if a window is returned then |location| will be
-  // updated to be relative to the origin of the window.
-  virtual ServerWindow* GetRootWindowContaining(gfx::Point* location) = 0;
+  // null if there is a no window containing |location_in_display|.
+  // |location_in_display| is in display coordinates and in pixels.
+  // |location_in_display| and |display_id| are updated if the window we
+  // found is on a different display than the originated display.
+  // TODO(riajiang): No need to update |location_in_display| and |display_id|
+  // after ozone drm can tell us the right display the cursor is on for
+  // drag-n-drop events. crbug.com/726470
+  virtual ServerWindow* GetRootWindowContaining(gfx::Point* location_in_display,
+                                                int64_t* display_id) = 0;
 
   // Called when event dispatch could not find a target. OnAccelerator may still
   // be called.
-  virtual void OnEventTargetNotFound(const ui::Event& event) = 0;
+  virtual void OnEventTargetNotFound(const ui::Event& event,
+                                     const int64_t display_id) = 0;
 
  protected:
   virtual ~EventDispatcherDelegate() {}