Update ppapi/ to use scoped_refptr<T>::get() rather than implicit "operator T*"

ppapi/proxy/url_loader_resource.cc

 // Copyright (c) 2013 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.
 
 #include "ppapi/proxy/url_loader_resource.h"
 
 #include "base/logging.h"
 #include "ppapi/c/pp_completion_callback.h"
 #include "ppapi/c/pp_errors.h"
 #include "ppapi/c/ppb_url_loader.h"
@@ skipping 307 matching lines @@
                      bytes_sent_, total_bytes_to_be_sent_,
                      bytes_received_, total_bytes_to_be_received_);
 }
 
 void URLLoaderResource::SetDefersLoading(bool defers_loading) {
   Post(RENDERER, PpapiHostMsg_URLLoader_SetDeferLoading(defers_loading));
 }
 
 int32_t URLLoaderResource::ValidateCallback(
     scoped_refptr<TrackedCallback> callback) {
-  DCHECK(callback);
+  DCHECK(callback.get());
   if (TrackedCallback::IsPending(pending_callback_))
     return PP_ERROR_INPROGRESS;
   return PP_OK;
 }
 
 void URLLoaderResource::RegisterCallback(
     scoped_refptr<TrackedCallback> callback) {
   DCHECK(!TrackedCallback::IsPending(pending_callback_));
   pending_callback_ = callback;
 }
@@ skipping 44 matching lines @@
   }
 
   // Reset for next time.
   user_buffer_ = NULL;
   user_buffer_size_ = 0;
   return bytes_to_copy;
 }
 
 }  // namespace proxy
 }  // namespace ppapi