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

ppapi/cpp/private/flash_clipboard.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_PRIVATE_FLASH_CLIPBOARD_H_
 #define PPAPI_CPP_PRIVATE_FLASH_CLIPBOARD_H_
 
 #include <string>
 #include <vector>
 
 #include "ppapi/c/private/ppb_flash_clipboard.h"
 #include "ppapi/cpp/var.h"
 
 namespace pp {
 
-class Instance;
+class InstanceHandle;
 
 namespace flash {
 
 class Clipboard {
  public:
   // Returns true if the required interface is available.
   static bool IsAvailable();
 
   // Returns true if the given format is available from the given clipboard.
-  static bool IsFormatAvailable(Instance* instance,
+  static bool IsFormatAvailable(const InstanceHandle& instance,
                                 PP_Flash_Clipboard_Type clipboard_type,
                                 PP_Flash_Clipboard_Format format);
 
   // Returns true on success, in which case |out| will be filled with
   // data read from the given clipboard in the given format.
-  static bool ReadData(Instance* instance,
+  static bool ReadData(const InstanceHandle& instance,
                        PP_Flash_Clipboard_Type clipboard_type,
                        PP_Flash_Clipboard_Format clipboard_format,
                        Var* out);
 
   // Returns true on success in which case all of |data| will be written to
   // the clipboard. Otherwise nothing will be written.
-  static bool WriteData(Instance* instance,
+  static bool WriteData(const InstanceHandle& instance,
                         PP_Flash_Clipboard_Type clipboard_type,
                         const std::vector<PP_Flash_Clipboard_Format>& formats,
                         const std::vector<Var>& data_items);
 };
 
 }  // namespace flash
 }  // namespace pp
 
 #endif  // PPAPI_CPP_PRIVATE_FLASH_CLIPBOARD_H_