Refactor XPCService initialization to make it easier to add more services
https://bugs.webkit.org/show_bug.cgi?id=108015

Reviewed by Dan Bernstein.

* Shared/EntryPointUtilities/mac/XPCService/XPCServiceBootstrapper.Development.h: Added.
(WebKit::XPCServiceEventHandler):
* Shared/EntryPointUtilities/mac/XPCService/XPCServiceBootstrapper.h: Added.
(WebKit::XPCServiceEventHandler):
Move bootstrapping to Shared (like we have for the legacy process). For now, we use
a macro to define the actual initialization point function to use, in the future, we
could consider alternatives, such as getting the function name from the bundle.

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

* WebProcess/EntryPoint/mac/XPCService/WebContentService.Development/WebContentServiceMain.Development.mm:
* WebProcess/EntryPoint/mac/XPCService/WebContentService/WebContentServiceMain.mm:
Simplify to use the new XPCServiceBootstrapper.

* WebProcess/EntryPoint/mac/XPCService/WebContentServiceEntryPoint.mm: Copied from Source/WebKit2/WebProcess/mac/WebProcessServiceEntryPoints.mm.
(initializeWebContentService):
* WebProcess/mac/WebProcessServiceEntryPoints.h: Removed.
* WebProcess/mac/WebProcessServiceEntryPoints.mm: Removed.
Move the entry point to where it belongs and extract the bootstrapping parts.


git-svn-id: http://svn.webkit.org/repository/webkit/trunk@140919 268f45cc-cd09-0410-ab3c-d52691b4dbfc