Compile the devtools grd file into a .pak file so we

tools/grit/resource_ids

 # Copyright (c) 2010 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.
 #
 # This file is used to assign starting resource ids for resources and strings
 # used by Chromium.  This is done to ensure that resource ids are unique
 # across all the grd files.  If you are adding a new grd file, please add
 # a new entry to this file.
 #
 # http://msdn.microsoft.com/en-us/library/t2zechd4(VS.71).aspx says that the
@@ skipping 109 matching lines @@
     "structures": [19000],
     "messages": [19010],
   },
 
   "chrome/browser/autofill/autofill_resources.grd": {
     "messages": [19500],
   },
   "chrome/browser/resources/sync_internals_resources.grd": {
     "includes": [20000],
   },
+  # This file is generated during the build.
+  "<(SHARED_INTERMEDIATE_DIR)/devtools/devtools_resources.grd": {
+    "includes": [20500],
+  }
 }