Support sharing of ContentMain and BrowserMain code with embedded use cases (try #3).

content/content_app.gypi

-# Copyright (c) 2011 The Chromium Authors. All rights reserved.
+# 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.
 
 {
   'include_dirs': [
     '..',
   ],
   'dependencies': [
     '../base/base.gyp:base',
     '../base/base.gyp:base_i18n',
     '../crypto/crypto.gyp:crypto',
     '../ui/ui.gyp:ui',
   ],
   'sources': [
     'app/content_main.cc',
-    'app/content_main.h',
+    'app/content_main_runner.cc',
     'app/startup_helper_win.cc',
+    'public/app/content_main.h',
     'public/app/content_main_delegate.h',
+    'public/app/content_main_runner.h',
     'public/app/startup_helper_win.h',
   ],
   'conditions': [
     ['OS=="win"', {
       'dependencies': [
         '../sandbox/sandbox.gyp:sandbox',
       ],
     }],
   ],
 }