Move the following files to content\public\plugin.

chrome/chrome.gyp

 # Copyright (c) 2011 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.
 {
   'variables': {
     'chromium_code': 1,
 
     'variables': {
       'version_py_path': 'tools/build/version.py',
       'version_path': 'VERSION',
@@ skipping 1090 matching lines @@
           ],
         },
         {
           # dylib for interposing Carbon calls in the plugin process.
           'target_name': 'plugin_carbon_interpose',
           'type': 'shared_library',
           'dependencies': [
             'chrome_dll',
           ],
           'sources': [
-            'browser/plugin_carbon_interpose_mac.cc',
+            '../content/plugin/plugin_carbon_interpose_mac.cc',
           ],
           'include_dirs': [
             '..',
           ],
           'link_settings': {
             'libraries': [
               '$(SDKROOT)/System/Library/Frameworks/Carbon.framework',
             ],
           },
           'xcode_settings': {
@@ skipping 597 matching lines @@
                 'destination': '<(PRODUCT_DIR)/default_apps',
                 'files': ['<@(default_apps_list)']
               },
             ],
           }],
         ],
       }],  # targets
     }],  # OS != "mac"
   ],  # 'conditions'
 }