Adds the UserInputMonitor implementation for Windows.

media/base/user_input_monitor.h

Index: media/base/user_input_monitor.h
diff --git a/media/base/user_input_monitor.h b/media/base/user_input_monitor.h
index 567907c76f8fc2cbad0554e060fff22a13c6dcf9..a4bf8781b8317fd41812573f22096b5df4b79b76 100644
--- a/media/base/user_input_monitor.h
+++ b/media/base/user_input_monitor.h
@@ -5,6 +5,7 @@
 #ifndef MEDIA_BASE_USER_INPUT_MONITOR_H_
 #define MEDIA_BASE_USER_INPUT_MONITOR_H_
 
+#include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/synchronization/lock.h"
@@ -24,7 +25,8 @@ namespace media {
 // it might be called on the browser UI/IO threads.
 // The object must outlive the browser UI/IO threads to make sure the callbacks
 // will not access a deleted object.
-class MEDIA_EXPORT UserInputMonitor {
+class MEDIA_EXPORT UserInputMonitor
+   : public base::RefCountedThreadSafe<UserInputMonitor> {
  public:
   // The interface to receive mouse movement events.
   class MEDIA_EXPORT MouseEventListener {
@@ -37,12 +39,11 @@ class MEDIA_EXPORT UserInputMonitor {
   };
 
   UserInputMonitor();
-  virtual ~UserInputMonitor();
 
   // Creates a platform-specific instance of UserInputMonitor.
   // |io_task_runner| is the task runner for an IO thread.
   // |ui_task_runner| is the task runner for a UI thread.
-  static scoped_ptr<UserInputMonitor> Create(
+  static scoped_refptr<UserInputMonitor> Create(
       const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner,
       const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner);
 
@@ -66,6 +67,9 @@ class MEDIA_EXPORT UserInputMonitor {
   virtual size_t GetKeyPressCount() const = 0;
 
  protected:
+  friend class base::RefCountedThreadSafe<UserInputMonitor>;
+  virtual ~UserInputMonitor();
+
   // Called by the platform-specific sub-classes to propagate the events to the
   // listeners.
   void OnMouseEvent(const SkIPoint& position);