Add a mode to OAuth2MintTokenFlow that fetches the messages to show to the user.

chrome/common/net/gaia/oauth2_access_token_fetcher.cc

 // 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.
 
 #include "chrome/common/net/gaia/oauth2_access_token_fetcher.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 24 matching lines @@
 
 static const char kGetAccessTokenBodyWithScopeFormat[] =
     "client_id=%s&"
     "client_secret=%s&"
     "grant_type=refresh_token&"
     "refresh_token=%s&"
     "scope=%s";
 
 static const char kAccessTokenKey[] = "access_token";
 
-static bool GetStringFromDictionary(const DictionaryValue* dict,
-                                    const std::string& key,
-                                    std::string* value) {
-  Value* json_value;
-  if (!dict->Get(key, &json_value))
-    return false;
-  if (json_value->GetType() != base::Value::TYPE_STRING)
-    return false;
-
-  StringValue* json_str_value = static_cast<StringValue*>(json_value);
-  json_str_value->GetAsString(value);
-  return true;
-}
-
 static GoogleServiceAuthError CreateAuthError(URLRequestStatus status) {
   CHECK(!status.is_success());
   if (status.status() == URLRequestStatus::CANCELED) {
     return GoogleServiceAuthError(GoogleServiceAuthError::REQUEST_CANCELED);
   } else {
     DLOG(WARNING) << "Could not reach Google Accounts servers: errno "
                   << status.error();
     return GoogleServiceAuthError::FromConnectionError(status.error());
   }
 }
@@ skipping 135 matching lines @@
   CHECK(source);
   CHECK(access_token);
   std::string data;
   source->GetResponseAsString(&data);
   base::JSONReader reader;
   scoped_ptr<base::Value> value(reader.Read(data, false));
   if (!value.get() || value->GetType() != base::Value::TYPE_DICTIONARY)
     return false;
 
   DictionaryValue* dict = static_cast<DictionaryValue*>(value.get());
-  return GetStringFromDictionary(dict, kAccessTokenKey, access_token);
+  return dict->GetString(kAccessTokenKey, access_token);
 }