Make ToplevelWindowEventFilter and WorkspaceEventFilter into event handlers.

ash/wm/workspace/workspace_event_filter_test_helper.cc

Index: ash/wm/workspace/workspace_event_filter_test_helper.cc
===================================================================
--- ash/wm/workspace/workspace_event_filter_test_helper.cc	(revision 155914)
+++ ash/wm/workspace/workspace_event_filter_test_helper.cc	(working copy)
@@ -1,19 +0,0 @@
-// 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/wm/workspace/workspace_event_filter_test_helper.h"
-
-namespace ash {
-namespace internal {
-
-WorkspaceEventFilterTestHelper::WorkspaceEventFilterTestHelper(
-    WorkspaceEventFilter* filter)
-    : filter_(filter) {
-}
-
-WorkspaceEventFilterTestHelper::~WorkspaceEventFilterTestHelper() {
-}
-
-}  // namespace internal
-}  // namespace ash