Provide a way to suppress implicit MIDL generation rules for actions

test/win/idl-rules/basic-idl.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'midl_out_dir': '<(SHARED_INTERMEDIATE_DIR)',
   },
   'target_defaults': {
     'configurations': {
@@ skipping 20 matching lines @@
       'include_dirs': [
         '<(midl_out_dir)',
       ],
       'msvs_settings': {
         'VCMIDLTool': {
           'OutputDirectory': '<(midl_out_dir)',
           'HeaderFileName': '<(RULE_INPUT_ROOT).h',
          },
       },
     },
+    {
+      'target_name': 'idl_explicit_action',
+      'type': 'none',
+      'sources': [
+        'Window.idl',
+      ],
+      'actions': [{
+        'action_name': 'blink_idl',
+        'explicit_idl_action': 1,

[scottmg, 2014/08/12 03:34:02]

you should add

'msvs_cygwin_shell': 0,

here.

+        'inputs': [
+          'Window.idl',
+          'idl_compiler.py',
+        ],
+        'outputs': [
+          '<(RULE_INPUT_ROOT).cpp',
+          '<(RULE_INPUT_ROOT).h',
+        ],
+        'action': [
+          'python',
+          'idl_compiler.py',
+          'Window.idl',
+        ],
+      }],
+    },
   ],
 }