Implement Composition.buildFromEvents()

tracing/tracing/ui/base/pie_chart.html

Index: tracing/tracing/ui/base/pie_chart.html
diff --git a/tracing/tracing/ui/base/pie_chart.html b/tracing/tracing/ui/base/pie_chart.html
index 7bacd583670ff35b750c176cf659725a103b261e..d9c5fd4a7af3d006414a48b02f3b3b9cec85afc9 100644
--- a/tracing/tracing/ui/base/pie_chart.html
+++ b/tracing/tracing/ui/base/pie_chart.html
@@ -30,6 +30,7 @@ tr.exportTo('tr.ui.b', function() {
 
     decorate: function() {
       ChartBase.prototype.decorate.call(this);
+      this.margin.top = 0;
       this.classList.add('pie-chart');
 
       this.data_ = undefined;
@@ -54,6 +55,9 @@ tr.exportTo('tr.ui.b', function() {
       return this.data_;
     },
 
+    get titleMarginPx() {
+      return 40;
+    },
 
     /**
      * @param {Array} data Data for the chart, where each element in the array
@@ -80,13 +84,6 @@ tr.exportTo('tr.ui.b', function() {
       this.updateContents_();
     },
 
-    get margin() {
-      var margin = {top: 0, right: 0, bottom: 0, left: 0};
-      if (this.chartTitle_)
-        margin.top += 40;
-      return margin;
-    },
-
     getMinSize: function() {
       this.updateContents_();