开刀的类名叫 PluginWidgetIOS，利用lldb可以得到：
(lldb) image lookup -r -s PluginWidgetIOS
7 symbols match the regular expression 'PluginWidgetIOS' in /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneSimulator.platform/Developer/SDKs/iPhoneSimulator6.1.sdk/System/Library/PrivateFrameworks/WebKit.framework/WebKit:
Address: WebKit[0x0003a5a0] (WebKit.__TEXT.__text + 231680)
Summary: WebKit`PluginWidgetIOS::~PluginWidgetIOS() Address: WebKit[0x0003a5b0] (WebKit.__TEXT.__text + 231696)
Summary: WebKit`PluginWidgetIOS::~PluginWidgetIOS() Address: WebKit[0x0003a6f0] (WebKit.__TEXT.__text + 232016)
Summary: WebKit`PluginWidgetIOS::platformLayer() const Address: WebKit[0x0003a750] (WebKit.__TEXT.__text + 232112)
Summary: WebKit`PluginWidgetIOS::willProvidePluginLayer() const Address: WebKit[0x0003a7b0] (WebKit.__TEXT.__text + 232208)
Summary: WebKit`PluginWidgetIOS::attachPluginLayer() Address: WebKit[0x0003a810] (WebKit.__TEXT.__text + 232304)
Summary: WebKit`PluginWidgetIOS::detachPluginLayer() Address: WebKit[0x001335e0] (WebKit.__DATA.__data + 560)
Summary: vtable for PluginWidgetIOS其中有用的信息是：
Address: WebKit[0x001335e0] (WebKit.__DATA.__data + 560)
Summary: vtable for PluginWidgetIOS用IDA打开WebCore的静态库，goto（快捷键g） vtable所在的地址 0x1335e0，可以看到：
__data:001335E0 ; `vtable for'PluginWidgetIOS __data:001335E0 __ZTV15PluginWidgetIOS db 0 ; DATA XREF: __nl_symbol_ptr:__ZTV15PluginWidgetIOS_ptr
