Switch remaining CoreMedia soft-linking in WebKit over to CoreMediaSoftLink.{cpp,h}. This gets rid of 1 instance of duplicate soft-linking code for CoreMedia.framework.
<rdar://problem/47464025>
Created attachment 359798 [details] Patch v1
Created attachment 359845 [details] Patch v2 (for landing)
Created attachment 359861 [details] Patch v3 (test Windows build fix)
Committed r240332: <https://trac.webkit.org/changeset/240332>