Revert "Trigger clean-up GCs between tests of Speedometer"

tools/perf/benchmarks/speedometer.py

Index: tools/perf/benchmarks/speedometer.py
diff --git a/tools/perf/benchmarks/speedometer.py b/tools/perf/benchmarks/speedometer.py
index b93c76ba4a7636dd6ad918360308833c03932a93..f463abc28d88a5538b5ffa5b9688c29a943269c2 100644
--- a/tools/perf/benchmarks/speedometer.py
+++ b/tools/perf/benchmarks/speedometer.py
@@ -43,7 +43,6 @@ class SpeedometerMeasurement(page_test.PageTest):
 
   def CustomizeBrowserOptions(self, options):
     keychain_metric.KeychainMetric.CustomizeBrowserOptions(options)
-    options.AppendExtraBrowserArgs(['--js-flags=--expose_gc'])
 
   def ValidateAndMeasurePage(self, page, tab, results):
     tab.WaitForDocumentReadyStateToBeComplete()
@@ -60,11 +59,6 @@ class SpeedometerMeasurement(page_test.PageTest):
           benchmarkClient._measuredValues.push(measuredValues);
           benchmarkClient._timeValues.push(measuredValues.total);
         };
-        benchmarkClient.willRunTest = function(suite, test) {
-          for (var i = 0; i < 5; i++) {
-            gc();
-          }
-        };
         benchmarkClient.iterationCount = %d;
         startTest();
         """ % iterationCount)