Remove implementation of Panels on OSes other than ChromeOS.

chrome/browser/ui/panels/panel_mouse_watcher.cc

-// Copyright (c) 2011 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 "chrome/browser/ui/panels/panel_mouse_watcher.h"
-
-#include "chrome/browser/ui/panels/panel_mouse_watcher_observer.h"
-#include "ui/gfx/geometry/point.h"
-
-PanelMouseWatcher::PanelMouseWatcher() {
-}
-
-PanelMouseWatcher::~PanelMouseWatcher() {
-}
-
-void PanelMouseWatcher::AddObserver(PanelMouseWatcherObserver* observer) {
-  bool already_started = observers_.might_have_observers();
-  observers_.AddObserver(observer);
-  if (!already_started)
-    Start();
-}
-
-void PanelMouseWatcher::RemoveObserver(PanelMouseWatcherObserver* observer) {
-  DCHECK(observers_.HasObserver(observer));
-  observers_.RemoveObserver(observer);
-  if (!observers_.might_have_observers())
-    Stop();
-}
-
-void PanelMouseWatcher::NotifyMouseMovement(const gfx::Point& mouse_position) {
-  FOR_EACH_OBSERVER(PanelMouseWatcherObserver, observers_,
-                    OnMouseMove(mouse_position));
-}