Issue #1486 - Move one straggler from PassthroughAPP code to its directory

adblockplus.gyp

 {
   'includes': [
     'defaults.gypi',
     'common/common.gypi',
   ],
 
   'variables': {
     'build_type%': 'devbuild',
     'build_version%': '',
   },
@@ skipping 109 matching lines @@
       'src/plugin/PluginDebug.cpp',
       'src/plugin/PluginDebug.h',
       'src/plugin/PluginDomTraverserBase.h',
       'src/plugin/PluginErrorCodes.h',
       'src/plugin/PluginFilter.cpp',
       'src/plugin/PluginFilter.h',
       'src/plugin/PluginMimeFilterClient.cpp',
       'src/plugin/PluginMimeFilterClient.h',
       'src/plugin/PluginMutex.cpp',
       'src/plugin/PluginMutex.h',
-      'src/plugin/PluginPassthroughObject.h',
       'src/plugin/PluginSettings.cpp',
       'src/plugin/PluginSettings.h',
       'src/plugin/PluginStdAfx.cpp',
       'src/plugin/PluginStdAfx.h',
       'src/plugin/PluginSystem.cpp',
       'src/plugin/PluginSystem.h',
       'src/plugin/PluginTabBase.cpp',
       'src/plugin/PluginTabBase.h',
       'src/plugin/PluginUserSettings.cpp',
       'src/plugin/PluginUserSettings.h',
       'src/plugin/PluginUtil.cpp',
       'src/plugin/PluginUtil.h',
       'src/plugin/PluginWbPassThrough.cpp',
       'src/plugin/PluginWbPassThrough.h',
       'src/plugin/Resource.h',
+      'src/plugin/passthroughapp/PassthroughObject.h',
       'src/plugin/passthroughapp/ProtocolCF.h',
       'src/plugin/passthroughapp/ProtocolCF.inl',
       'src/plugin/passthroughapp/ProtocolImpl.h',
       'src/plugin/passthroughapp/ProtocolImpl.inl',
       'src/plugin/passthroughapp/SinkPolicy.h',
       'src/plugin/passthroughapp/SinkPolicy.inl',
     ],
     'include_dirs': [
       '$(WindowsSDK_IncludePath)',
       '$(VCInstallDir)atlmfc/include',
@@ skipping 152 matching lines @@
       'Release': {
         'msvs_settings': {
           'VCLinkerTool': {
             'AdditionalDependencies': ['atls.lib'],
           },
         },
       },
     },
   }]
 }