Convert resources to take an instance key instead of an Instance*.

ppapi/cpp/mouse_lock.h

 // 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.
 
 #ifndef PPAPI_CPP_MOUSE_LOCK_H_
 #define PPAPI_CPP_MOUSE_LOCK_H_
 
 #include "ppapi/c/pp_stdint.h"
+#include "ppapi/cpp/instance_handle.h"
 
 /// @file
 /// This file defines the API for locking the target of mouse events to a
 /// specific module instance.
 
 namespace pp {
 
 class CompletionCallback;
-class Instance;
 
 /// This class allows you to associate the <code>PPP_MouseLock</code> and
 /// <code>PPB_MouseLock</code> C-based interfaces with an object. It associates
 /// itself with the given instance, and registers as the global handler for
 /// handling the <code>PPP_MouseLock</code> interface that the browser calls.
 ///
 /// You would typically use this class by inheritance on your instance or by
 /// composition.
 ///
 /// <strong>Example (inheritance):</strong>
@@ skipping 15 matching lines @@
 ///     MyInstance() : mouse_lock_(this) {
 ///     }
 ///
 ///     MyMouseLock mouse_lock_;
 ///   };
 /// </code>
 class MouseLock {
  public:
   /// A constructor for creating a <code>MouseLock</code>.
   ///
-  /// @param[in] instance The instance that will own the new
-  /// <code>MouseLock</code>.
-  explicit MouseLock(Instance* instance);
+  /// @param[in] instance The instance with which this resource will be
+  /// associated.
+  explicit MouseLock(const InstanceHandle& instance);
 
   /// Destructor.
   virtual ~MouseLock();
 
   /// PPP_MouseLock functions exposed as virtual functions for you to override.
   virtual void MouseLockLost() = 0;
 
   /// LockMouse() requests the mouse to be locked. The browser will permit
   /// mouse lock only while the tab is in fullscreen mode.
   ///
@@ skipping 17 matching lines @@
   /// @return An int32_t containing an error code from <code>pp_errors.h</code>.
   int32_t LockMouse(const CompletionCallback& cc);
 
   /// UnlockMouse causes the mouse to be unlocked, allowing it to track user
   /// movement again. This is an asynchronous operation. The module instance
   /// will be notified using the <code>PPP_MouseLock</code> interface when it
   /// has lost the mouse lock.
   void UnlockMouse();
 
  private:
-  Instance* associated_instance_;
+  InstanceHandle associated_instance_;
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_MOUSE_LOCK_H_