Add "bundle_data" target as first step for adding bundle support to gn.

tools/gn/toolchain.cc

 // Copyright (c) 2013 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.
 
 #include "tools/gn/toolchain.h"
 
 #include <stddef.h>
 #include <string.h>
 #include <utility>
 
@@ skipping 133 matching lines @@
     case Target::EXECUTABLE:
       return Toolchain::TYPE_LINK;
     case Target::SHARED_LIBRARY:
       return Toolchain::TYPE_SOLINK;
     case Target::LOADABLE_MODULE:
       return Toolchain::TYPE_SOLINK_MODULE;
     case Target::STATIC_LIBRARY:
       return Toolchain::TYPE_ALINK;
     case Target::SOURCE_SET:
       return TYPE_STAMP;
-    case Target::COPY_FILES:
     case Target::ACTION:
     case Target::ACTION_FOREACH:
+    case Target::BUNDLE_DATA:
+    case Target::COPY_FILES:
       return TYPE_STAMP;
     default:
       NOTREACHED();
       return Toolchain::TYPE_NONE;
   }
 }
 
 const Tool* Toolchain::GetToolForTargetFinalOutput(const Target* target) const {
   return tools_[GetToolTypeForTargetFinalOutput(target)].get();
 }