Group tags by id and transition.

Tag Id increments for each additional transition of the same type but
resets to zero as each processor is called. This fix groups tags by both
id and transition to avoid confusion.

Bug: b/198757467

Test: upload a trace with multiple types of transition, where
transitions have the same tag id.

Change-Id: Idad9c04dc5ac01faf0234d131cbb03364b2ccc36

tools/winscope/src/mixins/Timeline.js

@@ -142,10 +142,8 @@ export default {
     timelineTransitions() {
       const transitions = [];
 
-      //group tags by transition 'id' property
-      const groupedTags = _.mapValues(
-        _.groupBy(this.tags, 'id'), clist => clist.map(tag => _.omit(tag, 'id')))
-      ;
+      //group tags by transition and 'id' property
+      const groupedTags = _.groupBy(this.tags, tag => `"${tag.transition} ${tag.id}"`);
 
       for (const transitionId in groupedTags) {
         const id = groupedTags[transitionId];