Show diff in bootstrap timings

Author: rylev

site/static/compare.html

@@ -380,6 +380,10 @@ <h2>Comparing <span id="stat-header">{{stat}}</span> between <span id="before">{
                     <th>total</th>
                     <th v-if="bootstrapTotals.a">A: {{bootstrapTotals.a.toFixed(3)}}</th>
                     <th v-if="bootstrapTotals.b">B: {{bootstrapTotals.b.toFixed(3)}}</th>
+                    <th v-if="bootstrapTotals.a && bootstrapTotals.b"
+                        v-bind:class="diffClass(bootstrapTotals.b - bootstrapTotals.a)">
+                        {{(bootstrapTotals.b - bootstrapTotals.a).toFixed(3)}}
+                    </th>
                 </tr>
                 <template v-for="bootstrap in bootstraps">
                     <tr>
@@ -594,6 +598,16 @@ <h2>Comparing <span id="stat-header">{{stat}}</span> between <span id="before">{
                     }
                     return klass;
 
+                },
+                diffClass(diff) {
+                    let klass = "";
+                    if (diff > 1) {
+                        klass = 'positive';
+                    } else if (diff < -1) {
+                        klass = 'negative';
+                    }
+                    return klass;
+
                 },
                 detailedQueryLink(commit, bench, run) {
                     return `/detailed-query.html?commit=${commit}&benchmark=${bench}&run_name=${run}`;