Added isolates for core Telemetry, and Telemetry based GPU tests.

The telemetry_gpu_test isolate successfully runs -- with the appropriate
extra command line arguments -- all of the tests in
content/test/gpu/gpu_tests: context_lost, gpu_process,
hardware_accelerated_feature, pixel, maps, memory_test, and
webgl_conformance.

BUG=321878
R=maruel@chromium.org

Review URL: https://codereview.chromium.org/117403004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@242737 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 242737