1. In a Safari window, select some text in a webpage
2. Switch to another window (so that Safari window will be inactive).
3. Click anywhere in the Safari window to activate it back.
Selection stays in tact (not being cleared).
Selection gets cleared.
Created attachment 249613 [details]
Fixes the bug
Created attachment 249615 [details]
Fixed non-Mac builds
Per Andres' in-person comment, I'm replacing USE(APP_KIT) by PLATFORM(MAC).
Committed r182087: <http://trac.webkit.org/changeset/182087>