Clean up Assignment Create in BlimpClientContextImpl.

blimp/client/core/context/assignment_fetcher.cc

Index: blimp/client/core/context/assignment_fetcher.cc
diff --git a/blimp/client/core/context/assignment_fetcher.cc b/blimp/client/core/context/assignment_fetcher.cc
new file mode 100644
index 0000000000000000000000000000000000000000..e51c6fc34354ca5a69390adaea536afe3406f367
--- /dev/null
+++ b/blimp/client/core/context/assignment_fetcher.cc
@@ -0,0 +1,60 @@
+// 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.
+
+#include "blimp/client/core/context/assignment_fetcher.h"
+
+#include <string>
+#include <utility>
+
+#include "base/bind.h"
+#include "base/memory/ptr_util.h"
+#include "blimp/client/core/session/assignment_source.h"
+#include "blimp/client/core/session/identity_source.h"
+
+namespace blimp {
+namespace client {
+
+AssignmentFetcher::AssignmentFetcher(
+    scoped_refptr<base::SingleThreadTaskRunner> io_thread_task_runner,
+    scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner,
+    std::unique_ptr<IdentityProvider> identity_provider,
+    GURL assigner_url,
+    const AssignmentResultCallback& assignment_received_callback,
+    const AuthErrorCallback& error_callback)
+    : identity_source_(base::MakeUnique<IdentitySource>(
+          std::move(identity_provider),
+          error_callback,
+          base::Bind(&AssignmentFetcher::OnAuthTokenReceived,
+                     base::Unretained(this)))),
+      assignment_received_callback_(assignment_received_callback),
+      assigner_url_(assigner_url),
+      io_thread_task_runner_(io_thread_task_runner),
+      file_thread_task_runner_(file_thread_task_runner) {}
+
+AssignmentFetcher::~AssignmentFetcher() = default;
+
+void AssignmentFetcher::Fetch() {
+  // Start Blimp authentication flow. The OAuth2 token will be used in
+  // assignment source.
+  identity_source_->Connect();
+}
+
+IdentitySource* AssignmentFetcher::GetIdentitySource() {
+  return identity_source_.get();
+}
+
+void AssignmentFetcher::OnAuthTokenReceived(
+    const std::string& client_auth_token) {
+  if (!assignment_source_) {
+    assignment_source_.reset(new AssignmentSource(
+        assigner_url_, io_thread_task_runner_, file_thread_task_runner_));
+  }
+
+  VLOG(1) << "Trying to get assignment.";
+  assignment_source_->GetAssignment(client_auth_token,
+                                    assignment_received_callback_);
+}
+
+}  // namespace client
+}  // namespace blimp