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

google_apis/determine_use_official_keys.gypi

+# Copyright (c) 2013 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.
+
+# Include this .gypi in your target to dynamically set the
+# use_official_google_api_keys variable (unless it is already
+# explicitly set) and the associated preprocessor define.
+
+{
+  'variables': {
+    'variables': {
+      'conditions': [
+        # If use_official_google_api_keys is already set (to 0 or 1), we
+        # do none of the implicit checking.  If it is set to 1 and the
+        # internal keys file is missing, the build will fail at compile
+        # time.  If it is set to 0 and keys are not provided by other
+        # means, a warning will be printed at compile time.
+        ['use_official_google_api_keys==2', {
+            'use_official_google_api_keys%':
+              '<!(python <(DEPTH)/google_apis/build/check_internal.py <(DEPTH)/google_apis/internal/google_chrome_api_keys.h)',
+          }],
+      ]
+    },
+    'use_official_google_api_keys%': 'use_official_google_api_keys',
+  },
+  'conditions': [
+    ['use_official_google_api_keys==1', {
+        'defines': ['USE_OFFICIAL_GOOGLE_API_KEYS=1'],

[M-A Ruel, 2013/05/08 18:11:23]

align -2 :)

+      }],
+  ],
+}