Revert of Make results_dashboard send just one request per test run.

Revert of Make results_dashboard send just one request per test run. (https://codereview.chromium.org/217053012/)

Reason for revert:
I think this change is responsible for some buildbot failures.

http://build.chromium.org/p/chromium.gpu/builders/Mac%2010.8%20Release%20%28ATI%29/builds/19584

@@@STEP_TEXT@tab_capture_performance_tests@@@
@@@STEP_TEXT@<div class="BuildResultInfo">@@@
@@@STEP_TEXT@</div>@@@
@@@STEP_LOG_LINE@graphs.dat@{}@@@
@@@STEP_LOG_END_PERF@graphs.dat@tab_capture_performance@@@
Traceback (most recent call last):
  File "/b/build/scripts/slave/runtest.py", line 1743, in <module>
    sys.exit(main())
  File "/b/build/scripts/slave/runtest.py", line 1707, in main
    result = _MainMac(options, args)
  File "/b/build/scripts/slave/runtest.py", line 935, in _MainMac
    options.factory_properties.get('perf_config'))
  File "/b/build/scripts/slave/runtest.py", line 604, in _SendResultsToDashboard
    build_dir, supplemental_columns)
  File "/b/build/scripts/slave/results_dashboard.py", line 59, in SendResults
    supplemental_columns)
  File "/b/build/scripts/slave/results_dashboard.py", line 192, in _GetResultsJson
    _PrintLinkStep(url, master, perf_id, test_name, revision)
UnboundLocalError: local variable 'revision' referenced before assignment

Original issue's description:
> Make results_dashboard send just one request per test run.
> 
> The PerformanceLogs() method of the log processor classes returns a dictionary mapping "log file" names to lists of lines. Each one of those log files corresponds to one chart name.
> 
> Previously, we were invoking _SendResultsToDashboard for each "log file"; that is, each chart name.
> 
> With this change, we are now passing the whole dict returned by PerformanceLogs() and making just one request for all points in all charts for a given test run.
> 
> BUG=
> 
> Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=260698

TBR=stip@chromium.org,qyearsley@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=260714

[rlarocque, 2014-04-01 00:15:45]

Created Revert of Make results_dashboard send just one request per test run.

[commit-bot: I haz the power, 2014-04-01 00:15:51]

CQ is trying da patch. Follow status at
https://chromium-status.appspot.com/cq/rlarocque@chromium.org/219773006/1

[commit-bot: I haz the power, 2014-04-01 00:17:41]

Change committed as 260714