Isolate check_internal.py to the .gypi files that need it.

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 dd346a83c12a6446268b9c6b1f158e2a2055f606..9a6ec478b6582f97aa1a95988b27a5ed313f7535 100644
--- a/google_apis/google_apis.gyp
+++ b/google_apis/google_apis.gyp
@@ -13,6 +13,9 @@
     {
       'target_name': 'google_apis',
       'type': 'static_library',
+      'includes': [
+        'determine_use_official_keys.gypi',
+      ],
       'dependencies': [
         '../base/base.gyp:base',
         '../crypto/crypto.gyp:crypto',
@@ -45,9 +48,6 @@
             'GOOGLE_CLIENT_SECRET_REMOTING="<(google_default_client_secret)"',
           ]
         }],
-        ['use_official_google_api_keys==1', {
-          'defines': ['USE_OFFICIAL_GOOGLE_API_KEYS=1'],
-        }],
       ],
       'sources': [
         'gaia/gaia_auth_consumer.cc',