Sort the threads that have different name too and fall back to original sorting behavior

This created some test changes how we find the selected thread in comparison
profiles especially. But after thinking about it, I decided that the new
behavior is actually better for them. Previously we were always getting the
first track, but now we are getting the crowded one, which is usually the
diffing track.

Author: canova

src/profile-logic/tracks.js

@@ -835,9 +835,11 @@ function _defaultThreadOrder(
     const nameB = threads[b].name;
 
     if (nameA === nameB) {
+      // Sort by the activity, but keep the original order if the activity
+      // scores are the equal.
       return (
         threadActivityScores[b].boostedSampleScore -
-        threadActivityScores[a].boostedSampleScore
+          threadActivityScores[a].boostedSampleScore || a - b
       );
     }
 
@@ -861,7 +863,10 @@ function _defaultThreadOrder(
 
     // Otherwise keep the existing order. We don't return 0 to guarantee that
     // the sort is stable even if the sort algorithm isn't.
-    return a - b;
+    return (
+      threadActivityScores[b].boostedSampleScore -
+        threadActivityScores[a].boostedSampleScore || a - b
+    );
   });
   return threadOrder;
 }

src/test/store/profile-view.test.js

@@ -534,6 +534,10 @@ describe('actions/ProfileView', function () {
 
     describe('with a comparison profile', function () {
       it('selects the calltree tab when selecting the diffing track', function () {
+        const firstTrackReference = {
+          type: 'global',
+          trackIndex: 0,
+        };
         const diffingTrackReference = {
           type: 'global',
           trackIndex: 2,
@@ -545,6 +549,7 @@ describe('actions/ProfileView', function () {
         ]);
         const { getState, dispatch } = storeWithProfile(profile);
 
+        dispatch(ProfileView.selectTrackWithModifiers(firstTrackReference));
         dispatch(App.changeSelectedTab('flame-graph'));
         expect(UrlStateSelectors.getSelectedThreadIndexes(getState())).toEqual(
           new Set([0])

src/test/store/receive-profile.test.js

@@ -411,9 +411,9 @@ describe('actions/receive-profile', function () {
 
       store.dispatch(viewProfile(profile));
       expect(getHumanReadableTracks(store.getState())).toEqual([
-        'show [thread Empty default] SELECTED',
         'show [thread Empty default]',
-        'show [thread Diff between 1 and 2 comparison]',
+        'show [thread Empty default]',
+        'show [thread Diff between 1 and 2 comparison] SELECTED',
       ]);
     });
 
@@ -514,9 +514,9 @@ describe('actions/receive-profile', function () {
 
         store.dispatch(viewProfile(profile));
         expect(getHumanReadableTracks(store.getState())).toEqual([
-          'show [thread Empty default] SELECTED',
           'show [thread Empty default]',
-          'show [thread Diff between 1 and 2 comparison]',
+          'show [thread Empty default]',
+          'show [thread Diff between 1 and 2 comparison] SELECTED',
         ]);
       });
     });
@@ -571,15 +571,15 @@ describe('actions/receive-profile', function () {
           '  - show [thread Thread with 140 CPU]',
           '  - show [thread Thread with 160 CPU]',
           '  - show [thread Thread with 180 CPU]',
-          '  - show [thread Thread with 190 CPU] SELECTED',
+          '  - show [thread Thread with 190 CPU]',
           '  - show [thread Thread with 220 CPU]',
           '  - show [thread Thread with 230 CPU]',
           '  - show [thread Thread with 270 CPU]',
           '  - show [thread Thread with 310 CPU]',
           '  - show [thread Thread with 320 CPU]',
           '  - show [thread Thread with 330 CPU]',
           '  - show [thread Thread with 350 CPU]',
-          '  - show [thread Thread with 380 CPU]',
+          '  - show [thread Thread with 380 CPU] SELECTED',
         ]);
       });
 
@@ -634,15 +634,15 @@ describe('actions/receive-profile', function () {
           '  - show [thread Thread with 130 CPU]',
           '  - show [thread Thread with 140 CPU]',
           '  - show [thread Thread with 180 CPU]',
-          '  - show [thread Thread with 190 CPU] SELECTED',
+          '  - show [thread Thread with 190 CPU]',
           '  - show [thread Thread with 220 CPU]',
           '  - show [thread Thread with 230 CPU]',
           '  - show [thread Thread with 270 CPU]',
           '  - show [thread Thread with 310 CPU]',
           '  - show [thread Thread with 320 CPU]',
           '  - show [thread Thread with 330 CPU]',
           '  - show [thread Thread with 350 CPU]',
-          '  - show [thread Thread with 380 CPU]',
+          '  - show [thread Thread with 380 CPU] SELECTED',
         ]);
       });
     });
@@ -1899,9 +1899,9 @@ describe('actions/receive-profile', function () {
 
       store.dispatch(viewProfile(resultProfile));
       expect(getHumanReadableTracks(store.getState())).toEqual([
-        'show [thread Empty default] SELECTED',
         'show [thread Empty default]',
-        'show [thread Diff between 1 and 2 comparison]',
+        'show [thread Empty default]',
+        'show [thread Diff between 1 and 2 comparison] SELECTED',
       ]);
     });
 

src/test/store/useful-tabs.test.js

@@ -53,6 +53,12 @@ describe('getUsefulTabs', function () {
   it('shows only the call tree when a diffing track is selected', function () {
     const { profile } = getMergedProfileFromTextSamples(['A  B  C', 'A  B  B']);
     const { getState, dispatch } = storeWithProfile(profile);
+    dispatch({
+      type: 'SELECT_TRACK',
+      selectedThreadIndexes: new Set([0]),
+      selectedTab: 'calltree',
+      lastNonShiftClickInformation: null,
+    });
     expect(selectedThreadSelectors.getUsefulTabs(getState())).toEqual([
       'calltree',
       'flame-graph',