Add Mouse hover behavior to Mac Panels when minimized

chrome/browser/ui/panels/panel_mouse_watcher_timer.cc

Index: chrome/browser/ui/panels/panel_mouse_watcher_timer.cc
diff --git a/chrome/browser/ui/panels/panel_mouse_watcher_gtk.cc b/chrome/browser/ui/panels/panel_mouse_watcher_timer.cc
similarity index 52%
rename from chrome/browser/ui/panels/panel_mouse_watcher_gtk.cc
rename to chrome/browser/ui/panels/panel_mouse_watcher_timer.cc
index 9ae6002e10b6ee71be7b129867e2e0a1d0a5f810..089d3e9bd83b56b7dcab8208449b3a3f084708dd 100644
--- a/chrome/browser/ui/panels/panel_mouse_watcher_gtk.cc
+++ b/chrome/browser/ui/panels/panel_mouse_watcher_timer.cc
@@ -2,8 +2,6 @@
 // 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_gtk.h"
-
 #include "base/memory/singleton.h"
 #include "base/time.h"
 #include "base/timer.h"
@@ -11,14 +9,14 @@
 #include "chrome/browser/ui/panels/panel_mouse_watcher.h"
 #include "ui/gfx/screen.h"
 
-// A timer based implementation of PanelMouseWatcher.  Currently used on Gtk
-// but could be used on any platform.
-class PanelMouseWatcherGtk : public PanelMouseWatcher {
+// A timer based implementation of PanelMouseWatcher.  Currently used for Gtk
+// and Mac panels implementations.
+class PanelMouseWatcherTimer : public PanelMouseWatcher {
  public:
   // Returns the singleton instance.
-  static PanelMouseWatcherGtk* GetInstance();
+  static PanelMouseWatcherTimer* GetInstance();
 
-  virtual ~PanelMouseWatcherGtk();
+  virtual ~PanelMouseWatcherTimer();
 
  protected:
   virtual void Start();
@@ -28,50 +26,51 @@ class PanelMouseWatcherGtk : public PanelMouseWatcher {
   // Specifies the rate at which we want to sample the mouse position.
   static const int kMousePollingIntervalMs = 250;
 
-  PanelMouseWatcherGtk();
-  friend struct DefaultSingletonTraits<PanelMouseWatcherGtk>;
+  PanelMouseWatcherTimer();
+  friend struct DefaultSingletonTraits<PanelMouseWatcherTimer>;
 
   // Timer callback function.
   void DoWork();
-  friend class base::RepeatingTimer<PanelMouseWatcherGtk>;
+  friend class base::RepeatingTimer<PanelMouseWatcherTimer>;
 
-  // Timer used to track mouse movements.  Gtk does not provide an easy way of
-  // tracking mouse movements across applications.  So we use a timer to
+  // Timer used to track mouse movements. Some OSes do not provide an easy way
+  // of tracking mouse movements across applications.  So we use a timer to
   // accomplish the same.  This could also be more efficient as you end up
   // getting a lot of notifications when tracking mouse movements.
-  base::RepeatingTimer<PanelMouseWatcherGtk> timer_;
+  base::RepeatingTimer<PanelMouseWatcherTimer> timer_;
 
-  DISALLOW_COPY_AND_ASSIGN(PanelMouseWatcherGtk);
+  DISALLOW_COPY_AND_ASSIGN(PanelMouseWatcherTimer);
 };
 
 // static
 PanelMouseWatcher* PanelMouseWatcher::GetInstance() {
-  return PanelMouseWatcherGtk::GetInstance();
+  return PanelMouseWatcherTimer::GetInstance();
 }
 
 // static
-PanelMouseWatcherGtk* PanelMouseWatcherGtk::GetInstance() {
-  return Singleton<PanelMouseWatcherGtk>::get();
+PanelMouseWatcherTimer* PanelMouseWatcherTimer::GetInstance() {
+  return Singleton<PanelMouseWatcherTimer>::get();
 }
 
-PanelMouseWatcherGtk::PanelMouseWatcherGtk() : PanelMouseWatcher() {
+PanelMouseWatcherTimer::PanelMouseWatcherTimer() : PanelMouseWatcher() {
 }
 
-PanelMouseWatcherGtk::~PanelMouseWatcherGtk() {
+PanelMouseWatcherTimer::~PanelMouseWatcherTimer() {
+  DCHECK(!timer_.IsRunning());
 }
 
-void PanelMouseWatcherGtk::Start() {
+void PanelMouseWatcherTimer::Start() {
   DCHECK(!timer_.IsRunning());
   timer_.Start(FROM_HERE,
                base::TimeDelta::FromMilliseconds(kMousePollingIntervalMs),
-               this, &PanelMouseWatcherGtk::DoWork);
+               this, &PanelMouseWatcherTimer::DoWork);
 }
 
-void PanelMouseWatcherGtk::Stop() {
+void PanelMouseWatcherTimer::Stop() {
   DCHECK(timer_.IsRunning());
   timer_.Stop();
 }
 
-void PanelMouseWatcherGtk::DoWork() {
+void PanelMouseWatcherTimer::DoWork() {
   HandleMouseMovement(gfx::Screen::GetCursorScreenPoint());
 }