Android / Telemetry: final cleanup on perf_tests_helper.

This module has moved to build/util/lib/common.
Fix up remaining references and remove the old file.
Also, bring up a tiny change that went on the old module (units for histogram).

BUG=

Review URL: https://codereview.chromium.org/24253006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225532 0039d316-1c4b-4281-b951-d872f2087c98
Fix missing SYS_mmap when building Android on x86.

Review URL: https://codereview.chromium.org/24560002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225533 0039d316-1c4b-4281-b951-d872f2087c98
Rename CallbackRegistry to CallbackList

TBR=darin@chromium.org
R=ajwong@chromium.org, darin@chromium.org

Review URL: https://codereview.chromium.org/24648002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225534 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225533
cc: Check needs_offscreen_context() after UpdateLayers.

The SingleThreadProxy is checking if an offscreen context is needed
in a different order than the ThreadProxy. This makes it consistent
doing it after UpdateLayers(), so that a Layer::Update() method can
set the flag and have it affect the current frame.

R=piman
BUG=263069

Review URL: https://codereview.chromium.org/24659003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@225535 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 225535