Fix race issue in ArcAuthService.

chrome/browser/chromeos/arc/auth/arc_manual_auth_code_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_AUTH_ARC_MANUAL_AUTH_CODE_FETCHER_H_
+#define CHROME_BROWSER_CHROMEOS_ARC_AUTH_ARC_MANUAL_AUTH_CODE_FETCHER_H_
+
+#include <string>
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "chrome/browser/chromeos/arc/arc_support_host.h"
+#include "chrome/browser/chromeos/arc/auth/arc_auth_code_fetcher.h"
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+namespace arc {
+
+class ArcAuthContext;
+
+// Implements the auth token fetching procedure with user's "SIGN IN" button
+// click.
+class ArcManualAuthCodeFetcher : public ArcAuthCodeFetcher,
+                                 public ArcSupportHost::Observer {
+ public:
+  ArcManualAuthCodeFetcher(ArcAuthContext* context,
+                           ArcSupportHost* support_host);
+  ~ArcManualAuthCodeFetcher() override;
+
+  // ArcAuthCodeFetcher:
+  void Fetch(const FetchCallback& callback) override;
+
+ private:
+  void FetchInternal();
+
+  // Called when HTTP request gets ready.
+  void OnContextPrepared(net::URLRequestContextGetter* request_context_getter);
+
+  // ArcSupportHost::Observer:
+  void OnAuthSucceeded(const std::string& auth_code) override;
+  void OnRetryClicked() override;
+
+  ArcAuthContext* const context_;
+  ArcSupportHost* const support_host_;
+
+  FetchCallback pending_callback_;
+
+  base::WeakPtrFactory<ArcManualAuthCodeFetcher> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(ArcManualAuthCodeFetcher);
+};
+
+}  // namespace arc
+
+#endif  // CHROME_BROWSER_CHROMEOS_ARC_AUTH_ARC_MANUAL_AUTH_CODE_FETCHER_H_