Mac: Implement about:memory.

This implements about:memory on Mac. It calls /bin/ps to obtain information
about processes (this is Apple's officially supported "API"). Unfortunately, ps
provides fairly minimal information (rss and vsize); top is better, but not a
stable API -- it has changed greatly between Mac OS 10.5 and 10.6, and moreover
the 10.6 version is more limited in its output formatting.

BUG=9653
TEST=Go to about:memory under a variety of conditions (with a variety of browsers loaded).

Review URL: http://codereview.chromium.org/333008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@31168 0039d316-1c4b-4281-b951-d872f2087c98
16 files changed