Copying the following files AS-IS from google.glog r141:

- demangle.cc
- demangle.h
- symbolize.cc
- symbolize.h

The new functionality is a callback mechanism to allow users of
google.glog to provide their own implementation of
OpenObjectFileContainingPcAndGetStartAddress.

BUG=

Review URL: https://codereview.chromium.org/180163013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@254996 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 254996