Blimp OAuth2 token retreival on application start up.

blimp/client/core/session/BUILD.gn

 # 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.
 
 if (is_android) {
   import("//build/config/android/config.gni")
   import("//build/config/android/rules.gni")
 }
 
 source_set("session") {
   visibility = [
     "//blimp/client/*",
     "//blimp/engine:browser_tests",
   ]
 
   sources = [
     "assignment_source.cc",
     "assignment_source.h",
     "client_network_components.cc",
     "client_network_components.h",
     "cross_thread_network_event_observer.cc",
     "cross_thread_network_event_observer.h",
+    "identity_source.cc",
+    "identity_source.h",
     "network_event_observer.h",
   ]
 
   public_deps = [
     "//base",
     "//blimp/client/public:public_headers",
     "//blimp/net",
     "//components/safe_json",
+    "//google_apis",
     "//net",
     "//url",
   ]
 
   deps = [
     "//blimp/client/core:switches",
     "//blimp/common",
   ]
 }
 
 source_set("unit_tests") {
   visibility = [ "//blimp/client/core:unit_tests" ]
 
   testonly = true
 
-  sources = []
+  sources = [
+    "identity_source_unittest.cc",
+  ]
 
-  deps = []
+  deps = [
+    ":session",
+    "//base",
+    "//blimp/client/test:test",
+    "//google_apis:test_support",
+    "//testing/gmock",
+    "//testing/gtest",
+  ]
 
   data = []
 
   # TODO(dtrainor): Fix the test harness to allow this to run on Android.
   # See crbug.com/588240.
   if (is_linux) {
     sources += [ "assignment_source_unittest.cc" ]
 
     deps += [
-      ":session",
-      "//base",
       "//blimp/client/core:switches",
       "//blimp/common",
       "//blimp/common:test_support",
       "//components/safe_json:test_support",
       "//net:test_support",
-      "//testing/gmock",
-      "//testing/gtest",
       "//url",
     ]
 
     data += [
       "test_selfsigned_cert.pem",
       "//blimp/test/data/test_client_token",
     ]
   }
 }