Move FindPasteboard to ui/base/cocoa since it's used by two modules (content+chrome).

content/content_browser.gypi

 # 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.
 
 {
   'dependencies': [
     'browser/debugger/devtools_resources.gyp:devtools_resources',
     '../base/base.gyp:base_static',
     '../crypto/crypto.gyp:crypto',
     '../net/net.gyp:http_server',
@@ skipping 254 matching lines @@
     'browser/download/save_types.cc',
     'browser/download/save_types.h',
     'browser/fileapi/browser_file_system_helper.cc',
     'browser/fileapi/browser_file_system_helper.h',
     'browser/fileapi/chrome_blob_storage_context.cc',
     'browser/fileapi/chrome_blob_storage_context.h',
     'browser/fileapi/fileapi_message_filter.cc',
     'browser/fileapi/fileapi_message_filter.h',
     'browser/file_metadata_mac.h',
     'browser/file_metadata_mac.mm',
-    'browser/find_pasteboard.h',
-    'browser/find_pasteboard.mm',
     'browser/font_list_async.cc',
     'browser/gamepad/data_fetcher.h',
     'browser/gamepad/gamepad_provider.cc',
     'browser/gamepad/gamepad_provider.h',
     'browser/gamepad/gamepad_service.cc',
     'browser/gamepad/gamepad_service.h',
     'browser/gamepad/gamepad_standard_mappings.h',
     'browser/gamepad/gamepad_standard_mappings_linux.cc',
     'browser/gamepad/gamepad_standard_mappings_mac.mm',
     'browser/gamepad/platform_data_fetcher.h',
@@ skipping 602 matching lines @@
       ],
     }],
     ['input_speech==0', {
       'sources/': [
         ['exclude', '^browser/speech/'],
       ],
     }],
   ],
 }