Revert 227219 "Revert 226920 "Roll Clang 188423:191856.""

This relands the clang roll from r226920. The symbol issue
(http://crbug.com/304846) should be fixed by now, on the crash server side.

> Revert 226920 "Roll Clang 188423:191856."
> 
> Possibly broke crash symbolication on mac.
> 
> > Roll Clang 188423:191856.
> > 
> > Remove libprofile_rt from package.sh, it doesn't exist after LLVM r191835
> > 
> > BUG=290204,303886
> > R=thakis@chromium.org
> > TBR=net owner
> > NOTRY=true
> > 
> > Review URL: https://codereview.chromium.org/25875004
> 
> TBR=thakis@chromium.org
> 
> Review URL: https://codereview.chromium.org/26145004

TBR=thakis@chromium.org

Review URL: https://codereview.chromium.org/27092002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@228318 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 228318