This version contains improved debugger support for stepping out of
functions and a couple of minor performance improvements.

BUG=None
TEST=None

TBR=sgjesse@chromium.org
Review URL: http://codereview.chromium.org/2828001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@49670 0039d316-1c4b-4281-b951-d872f2087c98