Start disabling GYP by default in runhooks in some configurations.

build/gyp_chromium.py

Index: build/gyp_chromium.py
diff --git a/build/gyp_chromium.py b/build/gyp_chromium.py
index 3c975d6a4683920e5eea67d86424523c86623539..3beee064093a6b5bf048c1a2a7821dab1d0ed039 100644
--- a/build/gyp_chromium.py
+++ b/build/gyp_chromium.py
@@ -324,6 +324,20 @@ def main():
     print 'Updating projects from gyp files...'
     sys.stdout.flush()
 
+  # TODO(crbug.com/432967) - We are eventually going to switch GYP off
+  # by default for all Chromium builds, so this list of configurations
+  # will get broader and broader.
+  if ('--running-as-hook' in args and
+      os.environ.get('GYP_CHROMIUM_NO_ACTION', None) != '0' and
+      (sys.platform.startswith('linux') and not gyp_vars_dict)):
+    print 'GYP is now disabled in this configuration by default in runhooks.\n'
+    print 'If you really want to run this, either run it explicitly by hand\n'

[brettw, 2016/04/14 21:35:15]

"run it" -> "run build/gyp_chromium.py"
Most people don't know how to run GYP manually and this is much more convenient
for one-off testing than modifying your eng and re-running hooks.

+    print 'or set the environment variable GYP_CHROMIUM_NO_ACTION=0.'
+    sys.exit(0)
+
+  if '--running-as-hook' in args:
+    args.remove('--running-as-hook')
+
   # Off we go...
   gyp_rc = gyp.main(args)