events: Update scroll and touch 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 307 matching lines @@
       break;
     default:
       // We could also reach here because RootWindow may sometimes generate a
       // bunch of fake mouse events
       // (aura::RootWindow::PostMouseMoveEventAfterWindowChange).
       break;
   }
   return ui::ER_CONSUMED;
 }
 
-ui::EventResult DragDropController::OnTouchEvent(ui::TouchEvent* event) {
+void DragDropController::OnTouchEvent(ui::TouchEvent* event) {
   if (!IsDragDropInProgress())
-    return ui::ER_UNHANDLED;
+    return;
 
   // If current drag session was not started by touch, dont process this touch
   // event, but consume it so it does not interfere with current drag session.
   if (current_drag_event_source_ != ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH)
-    return ui::ER_CONSUMED;
+    event->StopPropagation();
 
-  switch (event->type()) {
-    case ui::ET_TOUCH_CANCELLED:
-      DragCancel();
-      break;
-    default:
-      break;
-  }
-  return ui::ER_UNHANDLED;
+  if (event->handled())
+    return;
+
+  if (event->type() == ui::ET_TOUCH_CANCELLED)
+    DragCancel();
 }
 
 void DragDropController::OnGestureEvent(ui::GestureEvent* event) {
   if (!IsDragDropInProgress())
     return;
 
   // If current drag session was not started by touch, dont process this touch
   // event, but consume it so it does not interfere with current drag session.
   if (current_drag_event_source_ !=
       ui::DragDropTypes::DRAG_EVENT_SOURCE_TOUCH) {
@@ skipping 147 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