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

ppapi/cpp/dev/file_chooser_dev.h

 // 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.
 
 #ifndef PPAPI_CPP_DEV_FILE_CHOOSER_DEV_H_
 #define PPAPI_CPP_DEV_FILE_CHOOSER_DEV_H_
 
 #include "ppapi/c/dev/ppb_file_chooser_dev.h"
 #include "ppapi/cpp/resource.h"
 
 namespace pp {
 
 class CompletionCallback;
 class FileRef;
-class Instance;
+class InstanceHandle;
 class Var;
 
 class FileChooser_Dev : public Resource {
  public:
   /// Creates an is_null() FileChooser object.
   FileChooser_Dev() {}
 
   /// This function creates a file chooser dialog resource.  The chooser is
   /// associated with a particular instance, so that it may be positioned on the
   /// screen relative to the tab containing the instance.  Returns 0 if passed
   /// an invalid instance.
   ///
   /// @param mode A PPB_FileChooser_Dev instance can be used to select a single
   /// file (PP_FILECHOOSERMODE_OPEN) or multiple files
   /// (PP_FILECHOOSERMODE_OPENMULTIPLE). Unlike the HTML5 <input type="file">
   /// tag, a PPB_FileChooser_Dev instance cannot be used to select a directory.
   /// In order to get the list of files in a directory, the
   /// PPB_DirectoryReader_Dev interface must be used.
   ///
   /// @param accept_mime_types A comma-separated list of MIME types such as
   /// "audio/ *,text/plain" (note there should be no space between the '/' and
   /// the '*', but one is added to avoid confusing C++ comments).  The dialog
   /// may restrict selectable files to the specified MIME types. An empty string
   /// or an undefined var may be given to indicate that all types should be
   /// accepted.
   ///
   /// TODO(darin): What if the mime type is unknown to the system?  The plugin
   /// may wish to describe the mime type and provide a matching file extension.
   /// It is more webby to use mime types here instead of file extensions.
-  FileChooser_Dev(const Instance* instance,
+  FileChooser_Dev(const InstanceHandle& instance,
                   PP_FileChooserMode_Dev mode,
                   const Var& accept_mime_types);
 
   FileChooser_Dev(const FileChooser_Dev& other);
 
   /// This function displays a previously created file chooser resource as a
   /// dialog box, prompting the user to choose a file or files. The callback is
   /// called with PP_OK on successful completion with a file (or files) selected
   /// or PP_ERROR_USERCANCEL if the user selected no file.
   ///
   /// @return PP_OK_COMPLETIONPENDING if request to show the dialog was
   /// successful, another error code from pp_errors.h on failure.
   virtual int32_t Show(const CompletionCallback& cc);
 
   /// After a successful completion callback call from Show, this method may be
   /// used to query the chosen files.  It should be called in a loop until it
   /// returns an is_null() FileRef.  Depending on the PP_ChooseFileMode
   /// requested when the FileChooser was created, the file refs will either
   /// be readable or writable.  Their file system type will be
   /// PP_FileSystemType_External.  If the user chose no files or cancelled the
   /// dialog, then this method will simply return an is_null() FileRef the
   /// first time it is called.
   virtual FileRef GetNextChosenFile() const;
 };
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_DEV_FILE_CHOOSER_DEV_H_