Add support for launching WebKit2 plugins using XPC
https://bugs.webkit.org/show_bug.cgi?id=108040

Reviewed by Dan Bernstein.

* Configurations/PluginService.32.xcconfig: Copied from Source/WebKit2/Configurations/WebContentService.xcconfig.
* Configurations/PluginService.64.xcconfig: Copied from Source/WebKit2/Configurations/WebContentService.xcconfig.
* Configurations/PluginService.Development.xcconfig: Copied from Source/WebKit2/Configurations/WebContentService.xcconfig.
Add configurations.

* PluginProcess/EntryPoint/mac/XPCService: Added.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.32: Added.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.32/Info.plist: Copied from Source/WebKit2/NetworkProcess/EntryPoint/mac/XPCService/NetworkService/Info.plist.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.32/PluginService.32.Main.mm: Copied from Source/WebKit2/NetworkProcess/EntryPoint/mac/XPCService/NetworkService/NetworkServiceMain.mm.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.64: Added.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.64/Info.plist: Copied from Source/WebKit2/NetworkProcess/EntryPoint/mac/XPCService/NetworkService/Info.plist.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.64/PluginService.64.Main.mm: Copied from Source/WebKit2/NetworkProcess/EntryPoint/mac/XPCService/NetworkService/NetworkServiceMain.mm.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.Development: Added.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.Development/Info.plist: Added.
* PluginProcess/EntryPoint/mac/XPCService/PluginService.Development/PluginService.Development.Main.mm: Added.
(main):
* PluginProcess/EntryPoint/mac/XPCService/PluginServiceEntryPoint.mm: Copied from Source/WebKit2/NetworkProcess/EntryPoint/mac/XPCService/NetworkServiceEntryPoint.mm.
(initializePluginService):
Add entry points.

* UIProcess/Launcher/mac/ProcessLauncherMac.mm:
(WebKit::serviceName):
Add plugin process service names and move into correct #ifdef.

* UIProcess/Plugins/mac/PluginProcessProxyMac.mm:
(WebKit::shouldUseXPC):
(WebKit::PluginProcessProxy::platformInitializeLaunchOptions):
Opt into xpc using the same rules as the WebProcess.

* WebKit2.xcodeproj/project.pbxproj:
Add files.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140929 268f45cc-cd09-0410-ab3c-d52691b4dbfc