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

BUG=163618

Review URL: https://codereview.chromium.org/11568006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@173166 0039d316-1c4b-4281-b951-d872f2087c98

23 files changed, 53 insertions, 67 deletions

diff --git a/ash/drag_drop/drag_drop_controller.cc b/ash/drag_drop/drag_drop_controller.cc
index 4248099..f3d0343 100644
--- a/ash/drag_drop/drag_drop_controller.cc
+++ b/ash/drag_drop/drag_drop_controller.cc
@@ -325,23 +325,20 @@ ui::EventResult DragDropController::OnMouseEvent(ui::MouseEvent* event) {
   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) {
diff --git a/ash/drag_drop/drag_drop_controller.h b/ash/drag_drop/drag_drop_controller.h
index 6fe58a1..bef79a0 100644
--- a/ash/drag_drop/drag_drop_controller.h
+++ b/ash/drag_drop/drag_drop_controller.h
@@ -67,7 +67,7 @@ class ASH_EXPORT DragDropController
   // Overridden from ui::EventHandler:
   virtual ui::EventResult OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // Overridden from aura::WindowObserver.
diff --git a/ash/launcher/launcher_tooltip_manager.cc b/ash/launcher/launcher_tooltip_manager.cc
index f99e552..dfc2a4b 100644
--- a/ash/launcher/launcher_tooltip_manager.cc
+++ b/ash/launcher/launcher_tooltip_manager.cc
@@ -278,11 +278,10 @@ ui::EventResult LauncherTooltipManager::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult LauncherTooltipManager::OnTouchEvent(ui::TouchEvent* event) {
+void LauncherTooltipManager::OnTouchEvent(ui::TouchEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
   if (widget_ && widget_->IsVisible() && widget_->GetNativeWindow() != target)
     Close();
-  return ui::ER_UNHANDLED;
 }
 
 void LauncherTooltipManager::OnGestureEvent(ui::GestureEvent* event) {
diff --git a/ash/launcher/launcher_tooltip_manager.h b/ash/launcher/launcher_tooltip_manager.h
index 8bb764f..a4e28c5 100644
--- a/ash/launcher/launcher_tooltip_manager.h
+++ b/ash/launcher/launcher_tooltip_manager.h
@@ -77,7 +77,7 @@ class ASH_EXPORT LauncherTooltipManager : public ui::EventHandler,
 protected:
   // ui::EventHandler overrides:
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // SessionStateObserver override:
diff --git a/ash/launcher/launcher_tooltip_manager_unittest.cc b/ash/launcher/launcher_tooltip_manager_unittest.cc
index c6d81dd..e1464da 100644
--- a/ash/launcher/launcher_tooltip_manager_unittest.cc
+++ b/ash/launcher/launcher_tooltip_manager_unittest.cc
@@ -164,16 +164,16 @@ TEST_F(LauncherTooltipManagerTest, ShouldHideForEvents) {
   ui::TouchEvent touch_event(
       ui::ET_TOUCH_PRESSED, gfx::Point(), 0, base::TimeDelta());
   SetEventTarget(root_window, &touch_event);
-  EXPECT_EQ(ui::ER_UNHANDLED,
-            event_handler->OnTouchEvent(&touch_event));
+  event_handler->OnTouchEvent(&touch_event);
+  EXPECT_FALSE(touch_event.handled());
   EXPECT_FALSE(TooltipIsVisible());
 
   // Shouldn't hide if the touch happens on the tooltip.
   ShowImmediately();
   views::Widget* tooltip_widget = GetTooltipWidget();
   SetEventTarget(tooltip_widget->GetNativeWindow(), &touch_event);
-  EXPECT_EQ(ui::ER_UNHANDLED,
-            event_handler->OnTouchEvent(&touch_event));
+  event_handler->OnTouchEvent(&touch_event);
+  EXPECT_FALSE(touch_event.handled());
   EXPECT_TRUE(TooltipIsVisible());
 
   // Should hide for gesture events.
diff --git a/ash/launcher/overflow_bubble.cc b/ash/launcher/overflow_bubble.cc
index d2f889e..06a0f52 100644
--- a/ash/launcher/overflow_bubble.cc
+++ b/ash/launcher/overflow_bubble.cc
@@ -74,7 +74,7 @@ class OverflowBubbleView : public views::BubbleDelegateView {
   virtual bool OnMouseWheel(const ui::MouseWheelEvent& event) OVERRIDE;
 
   // ui::EventHandler overrides:
-  virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
 
   // views::BubbleDelegate overrides:
   virtual gfx::Rect GetBubbleBounds() OVERRIDE;
@@ -185,11 +185,11 @@ bool OverflowBubbleView::OnMouseWheel(const ui::MouseWheelEvent& event) {
   return true;
 }
 
-ui::EventResult OverflowBubbleView::OnScrollEvent(ui::ScrollEvent* event) {
+void OverflowBubbleView::OnScrollEvent(ui::ScrollEvent* event) {
   ScrollByXOffset(-event->x_offset());
   ScrollByYOffset(-event->y_offset());
   Layout();
-  return ui::ER_HANDLED;
+  event->SetHandled();
 }
 
 gfx::Rect OverflowBubbleView::GetBubbleBounds() {
diff --git a/ash/magnifier/magnification_controller.cc b/ash/magnifier/magnification_controller.cc
index b7e90c1..0912e37 100644
--- a/ash/magnifier/magnification_controller.cc
+++ b/ash/magnifier/magnification_controller.cc
@@ -115,7 +115,7 @@ class MagnificationControllerImpl : virtual public MagnificationController,
 
   // ui::EventHandler overrides:
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
 
   aura::RootWindow* root_window_;
 
@@ -506,12 +506,13 @@ ui::EventResult MagnificationControllerImpl::OnMouseEvent(
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult MagnificationControllerImpl::OnScrollEvent(
+void MagnificationControllerImpl::OnScrollEvent(
     ui::ScrollEvent* event) {
   if (event->IsAltDown() && event->IsControlDown()) {
     if (event->type() == ui::ET_SCROLL_FLING_START ||
         event->type() == ui::ET_SCROLL_FLING_CANCEL) {
-      return ui::ER_CONSUMED;
+      event->StopPropagation();
+      return;
     }
 
     if (event->type() == ui::ET_SCROLL) {
@@ -519,11 +520,10 @@ ui::EventResult MagnificationControllerImpl::OnScrollEvent(
       float scale = GetScale();
       scale += scroll_event->y_offset() * kScrollScaleChangeFactor;
       SetScale(scale, true);
-      return ui::ER_CONSUMED;
+      event->StopPropagation();
+      return;
     }
   }
-
-  return ui::ER_UNHANDLED;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
diff --git a/ash/system/tray/tray_event_filter.cc b/ash/system/tray/tray_event_filter.cc
index 01a751b..e1a223c 100644
--- a/ash/system/tray/tray_event_filter.cc
+++ b/ash/system/tray/tray_event_filter.cc
@@ -36,12 +36,9 @@ ui::EventResult TrayEventFilter::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult TrayEventFilter::OnTouchEvent(ui::TouchEvent* event) {
-  if (event->type() == ui::ET_TOUCH_PRESSED &&
-      ProcessLocatedEvent(event)) {
-    return ui::ER_CONSUMED;
-  }
-  return ui::ER_UNHANDLED;
+void TrayEventFilter::OnTouchEvent(ui::TouchEvent* event) {
+  if (event->type() == ui::ET_TOUCH_PRESSED && ProcessLocatedEvent(event))
+    event->StopPropagation();
 }
 
 bool TrayEventFilter::ProcessLocatedEvent(ui::LocatedEvent* event) {
diff --git a/ash/system/tray/tray_event_filter.h b/ash/system/tray/tray_event_filter.h
index dd86f3b..65fec335 100644
--- a/ash/system/tray/tray_event_filter.h
+++ b/ash/system/tray/tray_event_filter.h
@@ -27,7 +27,7 @@ class TrayEventFilter : public ui::EventHandler {
 
   // Overridden from ui::EventHandler.
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
 
  private:
   // Returns true if the event is handled.
diff --git a/ash/tooltips/tooltip_controller.cc b/ash/tooltips/tooltip_controller.cc
index 1639419dd..21dcab5 100644
--- a/ash/tooltips/tooltip_controller.cc
+++ b/ash/tooltips/tooltip_controller.cc
@@ -302,7 +302,7 @@ ui::EventResult TooltipController::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult TooltipController::OnTouchEvent(ui::TouchEvent* event) {
+void TooltipController::OnTouchEvent(ui::TouchEvent* event) {
   // TODO(varunjain): need to properly implement tooltips for
   // touch events.
   // Hide the tooltip for touch events.
@@ -311,7 +311,6 @@ ui::EventResult TooltipController::OnTouchEvent(ui::TouchEvent* event) {
   if (tooltip_window_)
     tooltip_window_->RemoveObserver(this);
   tooltip_window_ = NULL;
-  return ui::ER_UNHANDLED;
 }
 
 void TooltipController::OnSessionStateEvent(
diff --git a/ash/tooltips/tooltip_controller.h b/ash/tooltips/tooltip_controller.h
index dc21527..d07f181 100644
--- a/ash/tooltips/tooltip_controller.h
+++ b/ash/tooltips/tooltip_controller.h
@@ -46,7 +46,7 @@ class ASH_EXPORT TooltipController : public aura::client::TooltipClient,
   // Overridden from ui::EventHandler.
   virtual ui::EventResult OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
 
   // Overridden from SessionStateController.
   virtual void OnSessionStateEvent(SessionStateObserver::EventType event)
diff --git a/ash/touch/touch_observer_hud.cc b/ash/touch/touch_observer_hud.cc
index 22dc029..176e52f 100644
--- a/ash/touch/touch_observer_hud.cc
+++ b/ash/touch/touch_observer_hud.cc
@@ -182,9 +182,9 @@ void TouchObserverHUD::UpdateTouchPointLabel(int index) {
   touch_labels_[index]->SetText(UTF8ToUTF16(string));
 }
 
-ui::EventResult TouchObserverHUD::OnTouchEvent(ui::TouchEvent* event) {
+void TouchObserverHUD::OnTouchEvent(ui::TouchEvent* event) {
   if (event->touch_id() >= kMaxTouchPoints)
-    return ui::ER_UNHANDLED;
+    return;
 
   if (event->type() != ui::ET_TOUCH_CANCELLED)
     touch_positions_[event->touch_id()] = event->root_location();
@@ -197,8 +197,6 @@ ui::EventResult TouchObserverHUD::OnTouchEvent(ui::TouchEvent* event) {
   UpdateTouchPointLabel(event->touch_id());
 
   widget_->SetSize(widget_->GetContentsView()->GetPreferredSize());
-
-  return ui::ER_UNHANDLED;
 }
 
 void TouchObserverHUD::OnWidgetClosing(views::Widget* widget) {
diff --git a/ash/touch/touch_observer_hud.h b/ash/touch/touch_observer_hud.h
index 03c1bac..acee910 100644
--- a/ash/touch/touch_observer_hud.h
+++ b/ash/touch/touch_observer_hud.h
@@ -35,7 +35,7 @@ class TouchObserverHUD : public ui::EventHandler,
   void UpdateTouchPointLabel(int index);
 
   // Overriden from ui::EventHandler:
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
 
   // Overridden from views::WidgetObserver:
   virtual void OnWidgetClosing(views::Widget* widget) OVERRIDE;
diff --git a/ash/wm/activation_controller.cc b/ash/wm/activation_controller.cc
index 274ab56..5544078 100644
--- a/ash/wm/activation_controller.cc
+++ b/ash/wm/activation_controller.cc
@@ -282,14 +282,12 @@ ui::EventResult ActivationController::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult ActivationController::OnScrollEvent(ui::ScrollEvent* event) {
-  return ui::ER_UNHANDLED;
+void ActivationController::OnScrollEvent(ui::ScrollEvent* event) {
 }
 
-ui::EventResult ActivationController::OnTouchEvent(ui::TouchEvent* event) {
+void ActivationController::OnTouchEvent(ui::TouchEvent* event) {
   if (event->type() == ui::ET_TOUCH_PRESSED)
     FocusWindowWithEvent(event);
-  return ui::ER_UNHANDLED;
 }
 
 void ActivationController::OnGestureEvent(ui::GestureEvent* event) {
diff --git a/ash/wm/activation_controller.h b/ash/wm/activation_controller.h
index 24bf0508..23fe737 100644
--- a/ash/wm/activation_controller.h
+++ b/ash/wm/activation_controller.h
@@ -77,8 +77,8 @@ class ASH_EXPORT ActivationController
   // Overridden from ui::EventHandler:
   virtual ui::EventResult OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // Implementation of ActivateWindow() with an Event.
diff --git a/ash/wm/system_gesture_event_filter.cc b/ash/wm/system_gesture_event_filter.cc
index 57aecd4..019cf53 100644
--- a/ash/wm/system_gesture_event_filter.cc
+++ b/ash/wm/system_gesture_event_filter.cc
@@ -65,11 +65,10 @@ ui::EventResult SystemGestureEventFilter::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult SystemGestureEventFilter::OnTouchEvent(ui::TouchEvent* event) {
+void SystemGestureEventFilter::OnTouchEvent(ui::TouchEvent* event) {
   aura::Window* target = static_cast<aura::Window*>(event->target());
   touch_uma_.RecordTouchEvent(target, *event);
   long_press_affordance_->ProcessEvent(target, event, event->touch_id());
-  return ui::ER_UNHANDLED;
 }
 
 void SystemGestureEventFilter::OnGestureEvent(ui::GestureEvent* event) {
diff --git a/ash/wm/system_gesture_event_filter.h b/ash/wm/system_gesture_event_filter.h
index 961929e..984604d 100644
--- a/ash/wm/system_gesture_event_filter.h
+++ b/ash/wm/system_gesture_event_filter.h
@@ -46,7 +46,7 @@ class SystemGestureEventFilter : public ui::EventHandler,
 
   // Overridden from ui::EventHandler:
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
   // Overridden from aura::WindowObserver.
diff --git a/ash/wm/user_activity_detector.cc b/ash/wm/user_activity_detector.cc
index ee6a2b7..4338acc 100644
--- a/ash/wm/user_activity_detector.cc
+++ b/ash/wm/user_activity_detector.cc
@@ -48,14 +48,12 @@ ui::EventResult UserActivityDetector::OnMouseEvent(ui::MouseEvent* event) {
   return ui::ER_UNHANDLED;
 }
 
-ui::EventResult UserActivityDetector::OnScrollEvent(ui::ScrollEvent* event) {
+void UserActivityDetector::OnScrollEvent(ui::ScrollEvent* event) {
   MaybeNotify();
-  return ui::ER_UNHANDLED;
 }
 
-ui::EventResult UserActivityDetector::OnTouchEvent(ui::TouchEvent* event) {
+void UserActivityDetector::OnTouchEvent(ui::TouchEvent* event) {
   MaybeNotify();
-  return ui::ER_UNHANDLED;
 }
 
 void UserActivityDetector::OnGestureEvent(ui::GestureEvent* event) {
diff --git a/ash/wm/user_activity_detector.h b/ash/wm/user_activity_detector.h
index b28b9ec..89a2518 100644
--- a/ash/wm/user_activity_detector.h
+++ b/ash/wm/user_activity_detector.h
@@ -37,8 +37,8 @@ class ASH_EXPORT UserActivityDetector : public ui::EventHandler {
   // ui::EventHandler implementation.
   virtual ui::EventResult OnKeyEvent(ui::KeyEvent* event) OVERRIDE;
   virtual ui::EventResult OnMouseEvent(ui::MouseEvent* event) OVERRIDE;
-  virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
   virtual void OnGestureEvent(ui::GestureEvent* event) OVERRIDE;
 
  private:
diff --git a/ash/wm/user_activity_detector_unittest.cc b/ash/wm/user_activity_detector_unittest.cc
index 2aa0ef5f..1e3105b 100644
--- a/ash/wm/user_activity_detector_unittest.cc
+++ b/ash/wm/user_activity_detector_unittest.cc
@@ -117,7 +117,8 @@ TEST_F(UserActivityDetectorTest, Basic) {
   ui::TouchEvent touch_event(
       ui::ET_TOUCH_PRESSED, gfx::Point(), 0, base::TimeDelta());
   SetEventTarget(window.get(), &touch_event);
-  EXPECT_EQ(ui::ER_UNHANDLED, detector_->OnTouchEvent(&touch_event));
+  detector_->OnTouchEvent(&touch_event);
+  EXPECT_FALSE(touch_event.handled());
   EXPECT_EQ(1, observer_->num_invocations());
   observer_->reset_stats();
 
diff --git a/ash/wm/window_modality_controller_unittest.cc b/ash/wm/window_modality_controller_unittest.cc
index 94a647c..65927af 100644
--- a/ash/wm/window_modality_controller_unittest.cc
+++ b/ash/wm/window_modality_controller_unittest.cc
@@ -298,9 +298,9 @@ class TouchTrackerWindowDelegate : public aura::test::TestWindowDelegate {
 
  private:
   // Overridden from aura::test::TestWindowDelegate.
-  virtual ui::EventResult OnTouchEvent(ui::TouchEvent* event) OVERRIDE {
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE {
     received_touch_ = true;
-    return aura::test::TestWindowDelegate::OnTouchEvent(event);
+    aura::test::TestWindowDelegate::OnTouchEvent(event);
   }
 
   bool received_touch_;
diff --git a/ash/wm/workspace/workspace_cycler.cc b/ash/wm/workspace/workspace_cycler.cc
index 3e6878b..1080bb0 100644
--- a/ash/wm/workspace/workspace_cycler.cc
+++ b/ash/wm/workspace/workspace_cycler.cc
@@ -39,16 +39,16 @@ WorkspaceCycler::~WorkspaceCycler() {
   ash::Shell::GetInstance()->RemovePreTargetHandler(this);
 }
 
-ui::EventResult WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
+void WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
   if (event->finger_count() != 3 ||
       event->type() != ui::ET_SCROLL) {
     scrubbing_ = false;
-    return ui::ER_UNHANDLED;
+    return;
   }
 
   if (!IsScrubbingEnabled()) {
     scrubbing_ = false;
-    return ui::ER_UNHANDLED;
+    return;
   }
 
   if (!scrubbing_) {
@@ -73,7 +73,8 @@ ui::EventResult WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
 
     scroll_x_ = 0;
     scroll_y_ = 0;
-    return ui::ER_HANDLED;
+    event->SetHandled();
+    return;
   }
 
   if (std::abs(scroll_x_) > kWorkspaceStepSize) {
@@ -86,7 +87,6 @@ ui::EventResult WorkspaceCycler::OnScrollEvent(ui::ScrollEvent* event) {
   }
 
   // The active workspace was not changed, do not consume the event.
-  return ui::ER_UNHANDLED;
 }
 
 }  // namespace internal
diff --git a/ash/wm/workspace/workspace_cycler.h b/ash/wm/workspace/workspace_cycler.h
index e828006..032f54c 100644
--- a/ash/wm/workspace/workspace_cycler.h
+++ b/ash/wm/workspace/workspace_cycler.h
@@ -24,7 +24,7 @@ class ASH_EXPORT WorkspaceCycler : public ui::EventHandler {
 
  private:
   // ui::EventHandler overrides:
-  virtual ui::EventResult OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
+  virtual void OnScrollEvent(ui::ScrollEvent* event) OVERRIDE;
 
   WorkspaceManager* workspace_manager_;