Make the file chooser use PP_ArrayOutput

ppapi/cpp/completion_callback.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_COMPLETION_CALLBACK_H_
 #define PPAPI_CPP_COMPLETION_CALLBACK_H_
 
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/cpp/logging.h"
@@ skipping 167 matching lines @@
 class CompletionCallbackWithOutput : public CompletionCallback {
  public:
   /// The type that will actually be stored in the completion callback. In the
   /// common case, this will be equal to the template parameter (for example,
   /// CompletionCallbackWithOutput<int> would obviously take an int*. However,
   /// resources are passed as PP_Resource, vars as PP_Var, and arrays as our
   /// special ArrayOutputAdapter object. The CallbackOutputTraits defines
   /// specializations for all of these cases.
   typedef typename internal::CallbackOutputTraits<T>::StorageType
       OutputStorageType;
+  typedef typename internal::CallbackOutputTraits<T>::APIArgType
+      APIArgType;
 
   /// The default constructor will create a blocking
   /// <code>CompletionCallback</code> that references the given output
   /// data.
   ///
   /// @param[in] output A pointer to the data associated with the callback. The
   /// caller must ensure that this pointer outlives the completion callback.
   ///
   /// <strong>Note:</strong> Blocking completion callbacks are only allowed from
   /// from background threads.
@@ skipping 32 matching lines @@
   /// @param[in] output A pointer to the data associated with the callback. The
   /// caller must ensure that this pointer outlives the completion callback.
   CompletionCallbackWithOutput(PP_CompletionCallback_Func func,
                                void* user_data,
                                int32_t flags,
                                OutputStorageType* output)
       : CompletionCallback(func, user_data, flags),
         output_(output) {
   }
 
-  OutputStorageType* output() const { return output_; }
+  APIArgType output() const {
+    return internal::CallbackOutputTraits<T>::StorageToAPIArg(*output_);
+  }
 
  private:
   OutputStorageType* output_;
 };
 
 /// BlockUntilComplete() is used in place of an actual completion callback
 /// to request blocking behavior. If specified, the calling thread will block
 /// until the function completes. Blocking completion callbacks are only
 /// allowed from background threads.
 ///
 /// @return A <code>CompletionCallback</code> corresponding to a NULL callback.
 CompletionCallback BlockUntilComplete();
 
 }  // namespace pp
 
 #endif  // PPAPI_CPP_COMPLETION_CALLBACK_H_