Add a webkit.scons file in between build\SConscript.main and...

chrome/chrome.scons

 # 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.
 
 __doc__ = """
 Master configuration for building chrome components.
 """
 
 Import('env')
 
+# Arrange for Hammer to add all programs to the 'chrome' Alias.
+env.Append(
+    COMPONENT_PROGRAM_GROUPS = ['chrome'],
+    COMPONENT_TEST_PROGRAM_GROUPS = ['chrome'],
+)
+
 sconscript_files = [
     'SConscript',
 
     'browser/browser.scons',
     'browser/debugger/debugger.scons',
     'common/common.scons',
     'common/ipc_tests.scons',
     'plugin/plugin.scons',
     'renderer/renderer.scons',
     'test/automated_ui_tests/automated_ui_tests.scons',
     'test/interactive_ui/interactive_ui_tests.scons',
     'test/ui/ui_tests.scons',
     'test/unit/unit_tests.scons',
 ]
 
 if env['PLATFORM'] != 'win32':
   remove_files = [
       'browser/debugger/debugger.scons',
       'test/automated_ui_tests/automated_ui_tests.scons',
       'test/interactive_ui/interactive_ui_tests.scons',
       'test/ui/ui_tests.scons',
   ]
   for remove in remove_files:
     sconscript_files.remove(remove)
 
 SConscript(sconscript_files, exports=['env'])