Add three missing test files to the .gn builds

google_apis/BUILD.gn

Index: google_apis/BUILD.gn
diff --git a/google_apis/BUILD.gn b/google_apis/BUILD.gn
index 4cf9fe459b4e81f08a03b132baf235439f9c1fff..064eca60952d6341c2e47358b3ea0dc905b7e737 100644
--- a/google_apis/BUILD.gn
+++ b/google_apis/BUILD.gn
@@ -218,6 +218,7 @@ source_set("test_support") {
 
 test("google_apis_unittests") {
   sources = [
+    "gaia/account_tracker_unittest.cc",
     "gaia/gaia_auth_fetcher_unittest.cc",
     "gaia/gaia_auth_util_unittest.cc",
     "gaia/gaia_oauth_client_unittest.cc",
@@ -225,6 +226,7 @@ test("google_apis_unittests") {
     "gaia/oauth2_access_token_fetcher_impl_unittest.cc",
     "gaia/oauth2_api_call_flow_unittest.cc",
     "gaia/oauth2_mint_token_flow_unittest.cc",
+    "gaia/oauth2_token_service_request_unittest.cc",
     "gaia/oauth2_token_service_unittest.cc",
     "gaia/oauth_request_signer_unittest.cc",
     "gaia/ubertoken_fetcher_unittest.cc",
@@ -253,6 +255,7 @@ test("google_apis_unittests") {
       "drive/drive_api_parser_unittest.cc",
       "drive/drive_api_requests_unittest.cc",
       "drive/drive_api_url_generator_unittest.cc",
+      "drive/files_list_request_runner_unittest.cc",
       "drive/request_sender_unittest.cc",
       "drive/request_util_unittest.cc",
       "drive/time_util_unittest.cc",