Revert 255151 "Make chrome_elf use thunks instead of function po..."

Revert 255151 "Make chrome_elf use thunks instead of function po..."
(Crashy on today's canary)
> Make chrome_elf use thunks instead of function pointers.
> 
> 1. Add functionality to ServiceResolverThunk to copy a thunk without patching.
> 2. Move chrome_elf thunk-handling code to a common location.
> 3. Use a thunk instead of a f'n ptr for redirects.
> 
> BUG=334379
> 
> Review URL: https://codereview.chromium.org/183833004

TBR=caitkp@chromium.org

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=255703

[Cait (Slow), 2014-03-07 22:06:33]

Committed patchset #1 manually as r255703 (tree was closed).