events: Update scroll and touch handlers to not return EventResult.

ui/app_list/contents_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/contents_view.h"
 
 #include <algorithm>
 
 #include "ui/app_list/app_list_constants.h"
 #include "ui/app_list/app_list_view.h"
@@ skipping 201 matching lines @@
             true);
       }
       event->SetHandled();
       return;
     }
     default:
       break;
   }
 }
 
-ui::EventResult ContentsView::OnScrollEvent(ui::ScrollEvent* event) {
+void ContentsView::OnScrollEvent(ui::ScrollEvent* event) {
   if (show_state_ != SHOW_APPS ||
       event->type() == ui::ET_SCROLL_FLING_CANCEL ||
       abs(event->x_offset()) < kMinScrollToSwitchPage) {
-    return ui::ER_UNHANDLED;
+    return;
   }
 
   if (!pagination_model_->has_transition()) {
     pagination_model_->SelectPageRelative(event->x_offset() > 0 ? -1 : 1,
                                           true);
   }
-  return ui::ER_HANDLED;
+  event->SetHandled();
 }
 
 }  // namespace app_list