Handle both OSX and iOS Simulator runtimes in the ASan postbuild script.
Also fixed a TODO: now the script bails out if a non-ASan executable is passed to it.

BUG=228243
R=thakis@chromium.org

Review URL: https://codereview.chromium.org/80603004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236738 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236738