Add a way to pass WebKit2 WKTypeRefs in Objective-C style user data messages
https://bugs.webkit.org/show_bug.cgi?id=116345

Reviewed by Anders Carlsson.

In order to efficiently send a WKImageRef to another process when using the
Objective-C WKConnection (or other user data messages), we need a way to encode
WKTypeRefs in the objective-c object graph. Thus was born WKTypeRefWrapper.

* Shared/mac/ObjCObjectGraphCoders.mm:
(WebKit::typeFromObject):
(WebKit::WebContextObjCObjectGraphEncoderImpl::encode):
(WebKit::WebContextObjCObjectGraphDecoderImpl::decode):
(WebKit::InjectedBundleObjCObjectGraphEncoderImpl::encode):
(WebKit::InjectedBundleObjCObjectGraphDecoderImpl::decode):
* UIProcess/API/mac/WKTypeRefWrapper.h: Added.
* UIProcess/API/mac/WKTypeRefWrapper.mm: Added.
(-[WKTypeRefWrapper initWithObject:]):
(-[WKTypeRefWrapper object]):
* WebKit2.xcodeproj/project.pbxproj:


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@150343 268f45cc-cd09-0410-ab3c-d52691b4dbfc