Revert 237833 "[Telemetry] Attempt to fix flaky jsgamebench time..."

[ RUN      ] ScrollActionTest.testScrollAction
Traceback (most recent call last):
  File "E:\b\build\slave\Win_7_Tests_x64__3_\build\src\tools\telemetry\telemetry\page\actions\scroll_unittest.py", line 66, in testScrollAction
    (scroll_position, scroll_height))
AssertionError: scroll_position=1427; scroll_height=1429

[  FAILED  ] ScrollActionTest.testScrollAction (3538 ms)

> [Telemetry] Attempt to fix flaky jsgamebench timeouts.
> 
> This benchmark can take 30 mins to run, but the buildbot times out after 20 mins
> of no output. So raise its timeout and change WaitFor to output a heartbeat so
> that the buildbot is happy with longer timeouts.
> 
> BUG=247476
> 
> Review URL: https://codereview.chromium.org/95513003

TBR=tonyg@chromium.org

Review URL: https://codereview.chromium.org/95793002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@237843 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 237843