Add code to mint OAuth tokens from login-scoped OAuth token.

chrome/common/net/gaia/oauth2_token_mint_fetcher.h

Index: chrome/common/net/gaia/oauth2_token_mint_fetcher.h
===================================================================
--- chrome/common/net/gaia/oauth2_token_mint_fetcher.h	(revision 0)
+++ chrome/common/net/gaia/oauth2_token_mint_fetcher.h	(revision 0)
@@ -0,0 +1,105 @@
+// 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 CHROME_COMMON_NET_GAIA_OAUTH2_TOKEN_MINT_FETCHER_H_
+#define CHROME_COMMON_NET_GAIA_OAUTH2_TOKEN_MINT_FETCHER_H_
+#pragma once
+
+#include <string>
+#include <vector>
+
+#include "base/gtest_prod_util.h"
+#include "base/memory/scoped_ptr.h"
+#include "chrome/common/net/gaia/oauth2_token_mint_consumer.h"
+#include "content/public/common/url_fetcher.h"
+#include "content/public/common/url_fetcher_delegate.h"
+#include "googleurl/src/gurl.h"
+
+class OAuth2TokenMintFetcherTest;
+
+namespace net {
+class URLRequestContextGetter;
+class URLRequestStatus;
+}
+
+// Abstracts the details to mint new OAuth2 tokens from OAuth2 login scoped
+// token.
+//
+// This class should be used on a single thread, but it can be whichever thread
+// that you like.
+// Also, do not reuse the same instance. Once Start() is called, the instance
+// should not be reused.
+//
+// Usage:
+// * Create an instance with a consumer.
+// * Call Start()
+// * The consumer passed in the constructor will be called on the same
+//   thread Start was called with the results.
+//
+// This class can handle one request at a time. To parallelize requests,
+// create multiple instances.
+class OAuth2TokenMintFetcher : public content::URLFetcherDelegate {

[jstritar, 2012/03/02 13:40:23]

Could this be OAuth2TokenMint to use the noun form of mint?

+ public:
+  OAuth2TokenMintFetcher(OAuth2TokenMintConsumer* consumer,
+                         net::URLRequestContextGetter* getter,
+                         const std::string& source);
+  virtual ~OAuth2TokenMintFetcher();
+
+  // Start the flow.
+  void Start(const std::string& oauth_login_access_token,
+             const std::string& client_id,
+             const std::vector<std::string>& scopes,
+             const std::string& origin);
+
+  void CancelRequest();
+
+  // Implementation of content::URLFetcherDelegate
+  virtual void OnURLFetchComplete(const content::URLFetcher* source) OVERRIDE;
+
+ private:
+  enum State {
+    INITIAL,
+    MINT_TOKEN_STARTED,
+    MINT_TOKEN_DONE,
+    ERROR_STATE,
+  };
+
+  // Helper methods for the flow.
+  void StartMintToken();
+  void EndMintToken(const content::URLFetcher* source);
+
+  // Helper mehtods for reporting back results.
+  void OnMintTokenSuccess(const std::string& access_token);
+  void OnMintTokenFailure(GoogleServiceAuthError error);
+
+  // Other helpers.
+  static GURL MakeMintTokenUrl();

[asargent_no_longer_on_chrome, 2012/03/01 00:53:36]

Given that this is called "MakeMintTokenUrl" and we generally speak about
"minting a token", would it make sense for this class to be named
"OAuth2MintTokenFetcher"? I guess "mint" can be either a verb (to do the
minting) or a noun (the place/thing that does generation).  No big deal either
way. 

[Munjal (Google), 2012/03/01 18:38:52]

Done.

[jstritar, 2012/03/02 13:40:23]

Yeah the names are a bit confusing. What do you think of saying 'Request'
instead of 'MintToken' here?

MakeRequestUrl
MakeRequestHeader
MakeRequestBody

Then the ParseMintTokenResponse method could be ParseResponse?

+  static std::string MakeMintTokenHeader(const std::string& access_token);
+  static std::string MakeMintTokenBody(const std::string& client_id,
+                                       const std::vector<std::string>& scopes,
+                                       const std::string& origin);
+  static bool ParseMintTokenResponse(const content::URLFetcher* source,
+                                     std::string* access_token);
+
+  // State that is set during construction.
+  OAuth2TokenMintConsumer* const consumer_;
+  net::URLRequestContextGetter* const getter_;
+  std::string source_;
+  State state_;
+
+  // While a fetch is in progress.
+  scoped_ptr<content::URLFetcher> fetcher_;
+  std::string oauth_login_access_token_;
+  std::string client_id_;
+  std::vector<std::string> scopes_;
+  std::string origin_;
+
+  friend class OAuth2TokenMintFetcherTest;
+  FRIEND_TEST_ALL_PREFIXES(OAuth2TokenMintFetcherTest,
+                           ParseMintTokenResponse);
+
+  DISALLOW_COPY_AND_ASSIGN(OAuth2TokenMintFetcher);
+};
+
+#endif  // CHROME_COMMON_NET_GAIA_OAUTH2_TOKEN_MINT_FETCHER_H_