Add GYP_CHROMIUM_NO_ACTION environment variable to gyp_chromium

build/gyp_chromium

Index: build/gyp_chromium
diff --git a/build/gyp_chromium b/build/gyp_chromium
index 3a4fb1af690597e4895e4ab91cc626ab06890417..a03fa344c17726c77c53f94184c48fc10caea010 100755
--- a/build/gyp_chromium
+++ b/build/gyp_chromium
@@ -82,6 +82,10 @@ def additional_include_files(args=[]):
 if __name__ == '__main__':
   args = sys.argv[1:]
 
+  if int(os.environ.get('GYP_CHROMIUM_NO_ACTION', 0)):
+    print 'Skipping gyp_chromium due to GYP_CHROMIUM_NO_ACTION env var.'
+    sys.exit(0)
+
   # Use the Psyco JIT if available.
   if psyco:
     psyco.profile()