arc: Pass auth token from Chrome to ARC instance.

chrome/browser/chromeos/arc/arc_auth_fetcher.h

+// Copyright 2016 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_BROWSER_CHROMEOS_ARC_ARC_AUTH_FETCHER_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_ARC_AUTH_FETCHER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/scoped_ptr.h"
+#include "net/url_request/url_fetcher_delegate.h"
+
+class GURL;
+class Profile;
+
+namespace net {
+class URLFetcher;
+}  // namespace net
+
+namespace arc {
+
+// Fetches ARC auth code. Fetching process starts automatically on creation.
+class ArcAuthFetcher : public net::URLFetcherDelegate {

[xiyuan, 2016/01/26 23:37:05]

Is it possible to extend GaiaAuthFetcher to support what we are trying to do
with the class? It looks like we can reuse
GaiaAuthFetcher::StartCookieForOAuthLoginTokenExchangeWithDeviceId [1]. The
difference is that we need to be able to pass a different client id and needs to
stop after auth code is fetched.

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/google_apis/gaia/g...

[khmel, 2016/01/27 22:36:21]

Honestly speaking I was thinking about this possibility and once you mention it
here did it. Please take a look into separate CL
(https://codereview.chromium.org/1644713002/).

+ public:
+  // Returns a result of ARC auth code fetching.
+  class Delegate {
+   public:
+    // Called when code was fetched.
+    virtual void OnAuthCodeFetched(const std::string& code) = 0;
+    // Called when additional UI authorization is required.
+    virtual void OnAuthCodeNeedUI() = 0;
+    // Called when auth code cannot be received.
+    virtual void OnAuthCodeFailed() = 0;
+  };
+
+  ArcAuthFetcher(Profile* profile, Delegate* delegate);
+  ~ArcAuthFetcher() override;
+
+  // net::URLFetcherDelegate overrides.
+  void OnURLFetchComplete(const net::URLFetcher* source) override;
+
+  // Helper function to compose target URL, also is used in test.
+  static GURL CreateURL(Profile* profile);
+
+ private:
+  void FetchAuthCode();
+  // Finds auth code in cookies.
+  static bool ParseAuthCode(const net::URLFetcher* source, std::string* code);
+
+  // Unowned pointers.
+  Profile* profile_;
+  Delegate* delegate_;
+
+  scoped_ptr<net::URLFetcher> auth_fetcher_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcAuthFetcher);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_AUTH_FETCHER_H_