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

ui/views/widget/native_widget_aura.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/views/widget/native_widget_aura.h"
 
 #include "base/bind.h"
 #include "base/string_util.h"
 #include "third_party/skia/include/core/SkRegion.h"
 #include "ui/aura/client/activation_client.h"
@@ skipping 823 matching lines @@
     return delegate_->OnMouseEvent(mwe) ? ui::ER_HANDLED : ui::ER_UNHANDLED;
   }
   return delegate_->OnScrollEvent(event);
 }
 
 ui::EventResult NativeWidgetAura::OnTouchEvent(ui::TouchEvent* event) {
   DCHECK(window_->IsVisible());
   return delegate_->OnTouchEvent(event);
 }
 
-ui::EventResult NativeWidgetAura::OnGestureEvent(ui::GestureEvent* event) {
+void NativeWidgetAura::OnGestureEvent(ui::GestureEvent* event) {
   DCHECK(window_->IsVisible());
-  return delegate_->OnGestureEvent(event);
+  delegate_->OnGestureEvent(event);
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // NativeWidgetAura, aura::ActivationDelegate implementation:
 
 bool NativeWidgetAura::ShouldActivate() const {
   return can_activate_ && delegate_->CanActivate();
 }
 
 void NativeWidgetAura::OnActivated() {
@@ skipping 202 matching lines @@
   return aura::Env::GetInstance()->is_mouse_button_down();
 }
 
 // static
 bool NativeWidgetPrivate::IsTouchDown() {
   return aura::Env::GetInstance()->is_touch_down();
 }
 
 }  // namespace internal
 }  // namespace views