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

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 538ac3ebd2e34a3319e371552553be8918c43508..a10198dc07c2c89a219263b4df6da3c9d67229e0 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1034,15 +1034,6 @@
         # TODO(jschuh): crbug.com/177664 Investigate Win64 pyauto build.
         'python_arch%': 'ia32',
       }],
-      # 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)',
-      }],
       ['os_posix==1 and OS!="mac" and OS!="ios"', {
         # Figure out the python architecture to decide if we build pyauto.
         'python_arch%': '<!(<(DEPTH)/build/linux/python_arch.sh <(sysroot)/usr/<(system_libdir)/libpython<(python_ver).so.1.0)',