events: Update mouse-event handlers to not return EventResult.

ash/magnifier/partial_magnification_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/magnifier/partial_magnification_controller.h"
 
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ui/aura/root_window.h"
 #include "ui/views/corewm/compound_event_filter.h"
@@ skipping 58 matching lines @@
     SetScale(kDefaultPartialMagnifiedScale);
   } else {
     SetScale(kNonPartialMagnifiedScale);
     is_enabled_ = enabled;
   }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // PartialMagnificationController: ui::EventHandler implementation
 
-ui::EventResult PartialMagnificationController::OnMouseEvent(
-    ui::MouseEvent* event) {
+void PartialMagnificationController::OnMouseEvent(ui::MouseEvent* event) {
   if (IsPartialMagnified() && event->type() == ui::ET_MOUSE_MOVED) {
     aura::Window* target = static_cast<aura::Window*>(event->target());
     aura::RootWindow* current_root = target->GetRootWindow();
     // TODO(zork): Handle the case where the event is captured on a different
     // display, such as when a menu is opened.
     gfx::Rect root_bounds = current_root->bounds();
 
     if (root_bounds.Contains(event->root_location())) {
       SwitchTargetRootWindow(current_root);
 
       OnMouseMove(event->root_location());
     }
   }
-
-  return ui::ER_UNHANDLED;
 }
 
 ////////////////////////////////////////////////////////////////////////////////
 // PartialMagnificationController: aura::WindowObserver implementation
 
 void PartialMagnificationController::OnWindowDestroying(
     aura::Window* window) {
   CloseMagnifierWindow();
 
   aura::RootWindow* new_root_window = GetCurrentRootWindow();
@@ skipping 101 matching lines @@
        iter != root_windows.end(); ++iter) {
     aura::RootWindow* root_window = *iter;
     if (root_window->ContainsPointInRoot(
             root_window->GetLastMouseLocationInRoot()))
       return root_window;
   }
   return NULL;
 }
 
 }  // namespace ash