events: Change gesture-event handler in EventHandler to not return any values.

ui/app_list/app_list_item_view.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 "ui/app_list/app_list_item_view.h"
 
 #include <algorithm>
 
 #include "base/utf_string_conversions.h"
 #include "ui/app_list/app_list_item_model.h"
@@ skipping 295 matching lines @@
   // Shows dragging UI when it's confirmed without waiting for the timer.
   if (ui_state_ != UI_STATE_DRAGGING &&
       apps_grid_view_->dragging() &&
       apps_grid_view_->IsDraggedView(this)) {
     mouse_drag_timer_.Stop();
     SetUIState(UI_STATE_DRAGGING);
   }
   return true;
 }
 
-ui::EventResult AppListItemView::OnGestureEvent(ui::GestureEvent* event) {
+void AppListItemView::OnGestureEvent(ui::GestureEvent* event) {
   switch (event->type()) {
     case ui::ET_GESTURE_SCROLL_BEGIN:
       if (touch_dragging_) {
         apps_grid_view_->InitiateDrag(this, AppsGridView::TOUCH, *event);
-        return ui::ER_CONSUMED;
+        event->SetHandled();
       }
       break;
     case ui::ET_GESTURE_SCROLL_UPDATE:
       if (touch_dragging_) {
         apps_grid_view_->UpdateDrag(this, AppsGridView::TOUCH, *event);
-        return ui::ER_CONSUMED;
+        event->SetHandled();
       }
       break;
     case ui::ET_GESTURE_SCROLL_END:
     case ui::ET_SCROLL_FLING_START:
       if (touch_dragging_) {
         SetTouchDragging(false);
         apps_grid_view_->EndDrag(false);
-        return ui::ER_CONSUMED;
+        event->SetHandled();
       }
       break;
     case ui::ET_GESTURE_LONG_PRESS:
       if (!apps_grid_view_->has_dragged_view())
         SetTouchDragging(true);
-      return ui::ER_CONSUMED;
+      event->SetHandled();
+      break;
     case ui::ET_GESTURE_END:
       if (touch_dragging_) {
         SetTouchDragging(false);
 
         gfx::Point location(event->location());
         ConvertPointToScreen(this, &location);
         ShowContextMenu(location, true);
       }
       break;
     default:
       break;
   }
-  return CustomButton::OnGestureEvent(event);
+  if (!event->handled())
+    CustomButton::OnGestureEvent(event);
 }
 
 }  // namespace app_list