Moves WorkspaceEventHandler to ash/common

ash/wm/workspace/workspace_event_handler_aura.cc

+// Copyright 2016 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_handler_aura.h"
+
+#include "ash/aura/wm_window_aura.h"
+#include "ui/aura/window.h"
+#include "ui/events/event.h"
+
+namespace ash {
+
+WorkspaceEventHandlerAura::WorkspaceEventHandlerAura(WmWindow* workspace_window)
+    : workspace_window_(workspace_window) {
+  workspace_window_->AddLimitedPreTargetHandler(this);
+}
+
+WorkspaceEventHandlerAura::~WorkspaceEventHandlerAura() {
+  workspace_window_->RemoveLimitedPreTargetHandler(this);
+}
+
+void WorkspaceEventHandlerAura::OnMouseEvent(ui::MouseEvent* event) {
+  WorkspaceEventHandler::OnMouseEvent(
+      event, WmWindowAura::Get(static_cast<aura::Window*>(event->target())));
+}
+
+void WorkspaceEventHandlerAura::OnGestureEvent(ui::GestureEvent* event) {
+  WorkspaceEventHandler::OnGestureEvent(
+      event, WmWindowAura::Get(static_cast<aura::Window*>(event->target())));
+}
+
+}  // namespace ash