More memory stats code cleanup:
Move GetSystemCommitCharge() into bsae\process_util*.
Kill PrintChromeMemoryUsageInfo(), which was only used by
reliability_tests.exe on Windows and whose stats are obsolete.
Delete the now-unnecessary chrome\test\perf\mem_usage* files.
BUG=none
TEST=none
Review URL: http://codereview.chromium.org/371025

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@31423 0039d316-1c4b-4281-b951-d872f2087c98

• base/process_util.h[diff]
• base/process_util_linux.cc[diff]
• base/process_util_mac.mm[diff]
• base/process_util_win.cc[diff]
• chrome/chrome.gyp[diff]
• chrome/test/memory_test/memory_test.cc[diff]
• chrome/test/perf/mem_usage.h[Deleted - diff]
• chrome/test/perf/mem_usage_linux.cc[Deleted - diff]
• chrome/test/perf/mem_usage_mac.cc[Deleted - diff]
• chrome/test/perf/mem_usage_win.cc[Deleted - diff]
• chrome/test/reliability/page_load_test.cc[diff]
• chrome_frame/chrome_frame.gyp[diff]
• chrome_frame/test/perf/chrome_frame_perftest.cc[diff]