ash: ozone: apply transformation to events outside the root window

ui/ozone/platform/dri/dri_window_manager.h

Index: ui/ozone/platform/dri/dri_window_manager.h
diff --git a/ui/ozone/platform/dri/dri_window_manager.h b/ui/ozone/platform/dri/dri_window_manager.h
index 5a03957b8cfcba18cf7c7a0841b5c844d3e2ab45..372bce76e165d7752a5daf41ada7402a9e950f8a 100644
--- a/ui/ozone/platform/dri/dri_window_manager.h
+++ b/ui/ozone/platform/dri/dri_window_manager.h
@@ -39,6 +39,16 @@ class DriWindowManager {
 
   DriCursor* cursor() const { return cursor_.get(); }
 
+  // Tries to set a given widget as the recipient for events. It will
+  // fail if there is already another widget as recipient.
+  void GrabEvents(gfx::AcceleratedWidget widget);
+
+  // Unsets a given widget as the recipient for events.
+  void UngrabEvents(gfx::AcceleratedWidget widget);
+
+  // Gets the current widget recipient of mouse events.
+  gfx::AcceleratedWidget event_grabber() const { return event_grabber_; }
+
  private:
   // Reset the cursor location based on the list of active windows.
   void ResetCursorLocation();
@@ -50,6 +60,8 @@ class DriWindowManager {
 
   scoped_ptr<DriCursor> cursor_;
 
+  gfx::AcceleratedWidget event_grabber_;
+
   DISALLOW_COPY_AND_ASSIGN(DriWindowManager);
 };