events: Update key-event handlers to not return EventResult.

ash/drag_drop/drag_drop_controller.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/drag_drop/drag_drop_controller.h"
 
 #include "ash/drag_drop/drag_drop_tracker.h"
 #include "ash/drag_drop/drag_image_view.h"
 #include "ash/shell.h"
 #include "ash/wm/coordinate_conversion.h"
@@ skipping 267 matching lines @@
 }
 
 void DragDropController::DragCancel() {
   DoDragCancel(kCancelAnimationDuration);
 }
 
 bool DragDropController::IsDragDropInProgress() {
   return !!drag_drop_tracker_.get();
 }
 
-ui::EventResult DragDropController::OnKeyEvent(ui::KeyEvent* event) {
+void DragDropController::OnKeyEvent(ui::KeyEvent* event) {
   if (IsDragDropInProgress() && event->key_code() == ui::VKEY_ESCAPE) {
     DragCancel();
-    return ui::ER_CONSUMED;
+    event->StopPropagation();
   }
-  return ui::ER_UNHANDLED;
 }
 
 ui::EventResult DragDropController::OnMouseEvent(ui::MouseEvent* event) {
   if (!IsDragDropInProgress())
     return ui::ER_UNHANDLED;
 
   // If current drag session was not started by mouse, dont process this mouse
   // event, but consume it so it does not interfere with current drag session.
   if (current_drag_event_source_ != ui::DragDropTypes::DRAG_EVENT_SOURCE_MOUSE)
     return ui::ER_CONSUMED;
@@ skipping 195 matching lines @@
     drag_window_->RemoveObserver(this);
   drag_window_ = NULL;
   drag_data_ = NULL;
   // Cleanup can be called again while deleting DragDropTracker, so use Pass
   // instead of reset to avoid double free.
   drag_drop_tracker_.Pass();
 }
 
 }  // namespace internal
 }  // namespace ash