Rename ValueSet* to HistogramSet*.

tracing/tracing/metrics/system_health/cpu_time_metric_test.html

Index: tracing/tracing/metrics/system_health/cpu_time_metric_test.html
diff --git a/tracing/tracing/metrics/system_health/cpu_time_metric_test.html b/tracing/tracing/metrics/system_health/cpu_time_metric_test.html
index 65616512ea8bcdecf03ffb84d96cce981f520c5d..9db9d0ed1f215ddd6e1b5aad084920a7e7aa3ced 100644
--- a/tracing/tracing/metrics/system_health/cpu_time_metric_test.html
+++ b/tracing/tracing/metrics/system_health/cpu_time_metric_test.html
@@ -7,7 +7,7 @@ found in the LICENSE file.
 
 <link rel="import" href="/tracing/core/test_utils.html">
 <link rel="import" href="/tracing/metrics/system_health/cpu_time_metric.html">
-<link rel="import" href="/tracing/value/value_set.html">
+<link rel="import" href="/tracing/value/histogram_set.html">
 
 <script>
 'use strict';
@@ -17,7 +17,7 @@ tr.b.unittest.testSuite(function() {
     var model = tr.c.TestUtils.newModel(function(model) {
       customizeModelCallback(model);
     });
-    var values = new tr.v.ValueSet();
+    var values = new tr.v.HistogramSet();
     tr.metrics.sh.cpuTimeMetric(values, model, opt_options);
     return tr.b.getOnlyElement(values).average;
   }