Make web_drag_source.cc compile on Posix.

chrome/browser/browser.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.
 
 Import('env')
 
 env = env.Clone()
 
 env.SConscript([
     '$CHROME_DIR/third_party/hunspell/using_hunspell.scons',
@@ skipping 696 matching lines @@
       'printing/printed_document.cc',
       'printing/printed_page.cc',
       'printing/printer_query.cc',
       'printing/win_printing_context.cc',
       'rlz/rlz.cc',
       'sandbox_policy.cc',
       'shell_integration.cc',
       'tab_contents/native_ui_contents.cc',
       'tab_contents/render_view_context_menu.cc',
       'tab_contents/view_source_contents.cc',
-      'tab_contents/web_drag_source.cc',
       'tab_contents/web_drop_target.cc',
       'task_manager.cc',
       'task_manager_resource_providers.cc',
       'views/download_tab_view.cc',
       'window_sizer.cc',
   )
 
   # Remove Windows-specific files on other platforms.
   input_files.Remove(
       'back_forward_menu_model_win.cc',
@@ skipping 149 matching lines @@
 
 xmldoc_tool_list = [
     MSVSTool('VCCLCompilerTool',
              XMLDocumentationFileName=('$(IntDir)/$(InputName)1.xdc'),
              ObjectFile='$(IntDir)/$(InputName)1.obj'),
 ]
 
 for filename in xmldoc_files:
   p.AddFileConfig(filename, 'Debug|Win32', xmldoc_tool_list)
   p.AddFileConfig(filename, 'Release|Win32', xmldoc_tool_list)