Sort GN files under components

For tools/sort_sources.py to be useful, existing GN files
should be sorted.

BUG=456014
TEST=everything should build as before

Review URL: https://codereview.chromium.org/934483002

Cr-Commit-Position: refs/heads/master@{#316447}
diff --git a/components/gcm_driver/BUILD.gn b/components/gcm_driver/BUILD.gn
index fa76389..e8c9a170 100644
--- a/components/gcm_driver/BUILD.gn
+++ b/components/gcm_driver/BUILD.gn
@@ -9,10 +9,10 @@
     "android/component_jni_registrar.h",
     "default_gcm_app_handler.cc",
     "default_gcm_app_handler.h",
-    "gcm_activity.cc",
-    "gcm_activity.h",
     "gcm_account_mapper.cc",
     "gcm_account_mapper.h",
+    "gcm_activity.cc",
+    "gcm_activity.h",
     "gcm_app_handler.cc",
     "gcm_app_handler.h",
     "gcm_backoff_policy.cc",