Exclude .idl files from the generated compilable files lists.

site_scons/site_tools/chromium_builders.py

 # Copyright (c) 2006-2008 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.
 
 """
 Tool module for adding, to a construction environment, Chromium-specific
 wrappers around Hammer builders.  This gives us a central place for any
 customization we need to make to the different things we build.
 """
 
@@ skipping 40 matching lines @@
         top[i] = new
 
 import __builtin__
 __builtin__.ChromeFileList = ChromeFileList
 
 non_compilable_suffixes = {
     'LINUX' : set([
         '.h',
         '.dat',
         '.rc',
+        '.idl',
     ]),
     'WINDOWS' : set([
         '.h',
         '.dat',
+        '.idl',
     ]),
 }
 
 def compilable(env, file):
   base, ext = os.path.splitext(str(file))
   if ext in non_compilable_suffixes[env['TARGET_PLATFORM']]:
     return False
   return True
 
 def compilable_files(env, sources):
@@ skipping 81 matching lines @@
   env.AddMethod(ChromeLibrary)
   env.AddMethod(ChromeStaticLibrary)
   env.AddMethod(ChromeSharedLibrary)
   env.AddMethod(ChromeObject)
   env.AddMethod(ChromeMSVSFolder)
   env.AddMethod(ChromeMSVSProject)
   env.AddMethod(ChromeMSVSSolution)
 
 def exists(env):
   return True