Mmm, pie

Mmm, pie.

Enable position independence by linking executables with the -pie linker flag.
This was previously done in r29592, but had to be backed out in r29604 because
Valgrind didn't understand slide. I don't know if Valgrind understands slide
or not on Mac OS X now, but for the time being, we'll do this in non-Valgrind
build configurations.

Position independence turns on address space layout randomization (ASLR).

No perf impact expected. We don't really have any significant quantity of
exported symbols for the loader to chew on.

BUG=16713
TEST=Everything should still work
Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=91243

[Mark Mentovai, 2011-06-30 20:22:23]

TVL isn’t here. Let’s try Nico.

[Nico, 2011-06-30 20:35:27]

I read the bug, but didn't see any notes on the perf impact of this change, or
why this is desirable (ASLR?) – can you add this to the CL description?

[Mark Mentovai, 2011-06-30 20:36:15]

ASLR. I’ll update.

[Nico, 2011-06-30 21:59:44]

LGTM with "no perf impact" in cl description.