Remove unused includes of plugin_list.h. Also remove unused ContentClient and webkit_support method…

webkit/support/platform_support_mac.mm

 // 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 "webkit/support/platform_support.h"
 
 #import <AppKit/AppKit.h>
 #include <AvailabilityMacros.h>
 #import <Foundation/Foundation.h>
 #import <objc/objc-runtime.h>
 
 #include "base/base_paths.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/mac/bundle_locations.h"
 #include "base/mac/mac_util.h"
 #include "base/path_service.h"
 #include "base/strings/string16.h"
 #include "base/strings/utf_string_conversions.h"
 #include "grit/webkit_resources.h"
 #include "ui/base/resource/data_pack.h"
-#include "webkit/plugins/npapi/plugin_list.h"
 #import "webkit/support/drt_application_mac.h"
 #import "webkit/support/mac/DumpRenderTreePasteboard.h"
 #include "webkit/support/test_webkit_platform_support.h"
 
 static ui::DataPack* g_resource_data_pack = NULL;
 
 namespace webkit_support {
 
 static NSAutoreleasePool* autorelease_pool;
 
@@ skipping 165 matching lines @@
       }
     }
     return resize_corner_data;
   }
   }
   base::StringPiece res;
   if (g_resource_data_pack)
     g_resource_data_pack->GetStringPiece(resource_id, &res);
   return res;
 }