without tcmalloc for testing purpose. The linker complains about
_set_new_mode so I remove the call from the code for now.

Note this change is different from the change Bradley is working
on which provides an option for building chrome without tcmalloc.
This change simply removes tcmalloc from the build. The plan is
checking it in, keeping it in trunk for 24 hours, and then
reverting it. The benefits are

- Having another round of performance comparison between build
with and w/o tcmalloc.
- Having a full run of UI test under purify with tcmalloc disabled.
- Getting a verified CL in case we'd like to build an alternative
dev build w/o tcmalloc for A/B test.


Review URL: http://codereview.chromium.org/159599

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@22080 0039d316-1c4b-4281-b951-d872f2087c98