Turn on eslint rule one-var and fix existing errors.

tracing/tracing/ui/analysis/related_events_test.html

Index: tracing/tracing/ui/analysis/related_events_test.html
diff --git a/tracing/tracing/ui/analysis/related_events_test.html b/tracing/tracing/ui/analysis/related_events_test.html
index b6e918832fca9c9b845f3cd4d34547f23157504b..8f327d6380c4ec332b052584d51779ca6840367f 100644
--- a/tracing/tracing/ui/analysis/related_events_test.html
+++ b/tracing/tracing/ui/analysis/related_events_test.html
@@ -126,7 +126,9 @@ tr.b.unittest.testSuite(function() {
     this.addHTMLOutput(viewEl);
     tr.b.forceAllPendingTasksToRunForTest();
 
-    var inFlows, outFlows, internalFlows;
+    var inFlows;
+    var outFlows;
+    var internalFlows;
     viewEl.$.table.tableRows.forEach(function(row) {
       if (row.type === 'Incoming flow') {
         assert.isUndefined(inFlows);
@@ -157,7 +159,9 @@ tr.b.unittest.testSuite(function() {
     this.addHTMLOutput(viewEl);
     tr.b.forceAllPendingTasksToRunForTest();
 
-    var precedingEvents, followingEvents, allEvents;
+    var precedingEvents;
+    var followingEvents;
+    var allEvents;
     viewEl.$.table.tableRows.forEach(function(row) {
       if (row.type === 'Preceding events') {
         assert.isUndefined(precedingEvents);