tools/sort_sources.py: sort C++ source file names in build files.

google_apis/google_apis.gyp

Index: google_apis/google_apis.gyp
diff --git a/google_apis/google_apis.gyp b/google_apis/google_apis.gyp
index 7383181cf8a9dfa1567233e6deb503c5c0bc2f66..7859a73780939b13d366c6616abdbb16e1463c75 100644
--- a/google_apis/google_apis.gyp
+++ b/google_apis/google_apis.gyp
@@ -92,11 +92,9 @@
         'gaia/identity_provider.h',
         'gaia/merge_session_helper.cc',
         'gaia/merge_session_helper.h',
-        'gaia/oauth_request_signer.cc',
-        'gaia/oauth_request_signer.h',
         'gaia/oauth2_access_token_consumer.h',
-        'gaia/oauth2_access_token_fetcher.h',
         'gaia/oauth2_access_token_fetcher.cc',
+        'gaia/oauth2_access_token_fetcher.h',
         'gaia/oauth2_access_token_fetcher_impl.cc',
         'gaia/oauth2_access_token_fetcher_impl.h',
         'gaia/oauth2_api_call_flow.cc',
@@ -107,6 +105,8 @@
         'gaia/oauth2_token_service.h',
         'gaia/oauth2_token_service_request.cc',
         'gaia/oauth2_token_service_request.h',
+        'gaia/oauth_request_signer.cc',
+        'gaia/oauth_request_signer.h',
         'gaia/ubertoken_fetcher.cc',
         'gaia/ubertoken_fetcher.h',
         'google_api_keys.cc',
@@ -132,20 +132,20 @@
         '..',
       ],
       'sources': [
-        'google_api_keys_unittest.cc',
         'gaia/account_tracker_unittest.cc',
         'gaia/gaia_auth_fetcher_unittest.cc',
         'gaia/gaia_auth_util_unittest.cc',
         'gaia/gaia_oauth_client_unittest.cc',
         'gaia/google_service_auth_error_unittest.cc',
         'gaia/merge_session_helper_unittest.cc',
-        'gaia/oauth_request_signer_unittest.cc',
         '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',
+        'google_api_keys_unittest.cc',
       ],
       'conditions': [
         ['enable_extensions==1', {