Rename Histogram.add() to addSample().

tracing/tracing/metrics/system_health/loading_metric.html

Index: tracing/tracing/metrics/system_health/loading_metric.html
diff --git a/tracing/tracing/metrics/system_health/loading_metric.html b/tracing/tracing/metrics/system_health/loading_metric.html
index 3feadf24b4506c47cdf04785e790dd0c100fdbe3..41f1c7666f9a356525e965a8bc726742f43af7b9 100644
--- a/tracing/tracing/metrics/system_health/loading_metric.html
+++ b/tracing/tracing/metrics/system_health/loading_metric.html
@@ -240,8 +240,7 @@ tr.exportTo('tr.metrics.sh', function() {
           continue;
 
         var timeToEvent = ev.start - navigationStartEvent.start;
-        histogram.add(timeToEvent, tr.v.d.DiagnosticMap.fromObject(
-            {url: new tr.v.d.Generic(url)}));
+        histogram.addSample(timeToEvent, {url: new tr.v.d.Generic(url)});
       }
       values.addValue(new tr.v.NumericValue(metric.valueName, histogram,
           {description: metric.description}));
@@ -284,8 +283,8 @@ tr.exportTo('tr.metrics.sh', function() {
     diagnosticDict.interactive = firstInteractive;
     diagnosticDict.pid = rendererHelper.pid;
     var timeToFirstInteractive = firstInteractive - navigationStartTime;
-    histogram.add(timeToFirstInteractive, tr.v.d.DiagnosticMap.fromObject(
-        {breakdown: new tr.v.d.Generic(diagnosticDict)}));
+    histogram.addSample(timeToFirstInteractive,
+        {breakdown: new tr.v.d.Generic(diagnosticDict)});
   }
 
   /**
@@ -331,10 +330,8 @@ tr.exportTo('tr.metrics.sh', function() {
       var diagnosticDict = rendererHelper.generateTimeBreakdownTree(
           navigationStart.start, fmpMarkerEvent.start);
       diagnosticDict.url = url;
-      firstMeaningfulPaintHistogram.add(
-          timeToFirstMeaningfulPaint,
-          tr.v.d.DiagnosticMap.fromObject(
-              {breakdown: new tr.v.d.Generic(diagnosticDict)}));
+      firstMeaningfulPaintHistogram.addSample(timeToFirstMeaningfulPaint,
+          {breakdown: new tr.v.d.Generic(diagnosticDict)});
       return {firstMeaningfulPaint: fmpMarkerEvent.start, url: url};
     }