Enable memory profiler on Linux when TC_MALLOC is enabled.

Enable memory profiler on Linux when TC_MALLOC is enabled.

Added a tc_malloc memory extension to get bytes allocated on
current thread (GetBytesAllocatedOnCurrentThread API call).

R=jam@chromium.org,jar@chromium.org
BUG=139667
TEST=test about:profiler after setting the env variable 
     CHROME_PROFILER_TIME=1. In about:profiler, it will
     show the memory allocated per thread. This change
     impacts linux only.

This is same as the following previously approved CL. Added
needed BASE_EXPORT for kAlternateProfilerTime and
SetAlternateTimeSource.

the https://chromiumcodereview.appspot.com/10820063/

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=150477

[ramant (doing other things), 2012-08-07 18:02:52]

Hi John Abd-El-Malek, jar,
  This is same change as the CL you had approved. Added BASE_EXPORT to fix the
problem (it was reverted yesterday 
https://chromiumcodereview.appspot.com/10855010. Failure was in
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%2...).

  Not 100% sure why CQ and trybots didn't fail with the previous CL.

thanks
raman

[jam, 2012-08-07 20:35:51]

lgtm

[jar (doing other things), 2012-08-07 22:07:17]

lgtm

[commit-bot: I haz the power, 2012-08-07 23:11:57]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtenneti@chromium.org/10834199/1

[commit-bot: I haz the power, 2012-08-07 23:30:51]

Try job failure for 10834199-1 (retry) on win for step "compile" (clobber
build).
It's a second try, previously, step "compile" failed.
http://build.chromium.org/p/tryserver.chromium/buildstatus?builder=win&number...

[commit-bot: I haz the power, 2012-08-07 23:54:14]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rtenneti@chromium.org/10834199/5004

[commit-bot: I haz the power, 2012-08-08 01:27:05]

Change committed as 150477