DevTools -> Memory Tab -> Allowing to edit a title of a heap snapshot

third_party/WebKit/Source/devtools/front_end/profiler/HeapSnapshotView.js

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 589 matching lines @@
     const multipleSnapshots = this._profiles().length > 1;
     this._perspectiveSelect.removeOptions();
     this._perspectives.forEach((perspective, index) => {
       if (multipleSnapshots || perspective !== this._comparisonPerspective)
         this._perspectiveSelect.createOption(perspective.title(), '', String(index));
     });
   }
 
   _updateBaseOptions() {
     var list = this._profiles();
-    // We're assuming that snapshots can only be added.
-    if (this._baseSelect.size() === list.length)
-      return;
+    this._baseSelect.removeOptions();
 
-    for (var i = this._baseSelect.size(), n = list.length; i < n; ++i) {
+    for (var i = 0; i < list.length; ++i) {

[alph, 2017/07/07 22:37:25]

nit: for (var item of list)

       var title = list[i].title;
       this._baseSelect.createOption(title);
     }
   }
 
   _updateFilterOptions() {
     var list = this._profiles();
-    // We're assuming that snapshots can only be added.
-    if (this._filterSelect.size() - 1 === list.length)
-      return;
+    this._filterSelect.removeOptions();

[alph, 2017/07/07 22:37:25]

This will kill the current selection, so the view content won't match the filter
selection. We need to save/restore it.

 
-    if (!this._filterSelect.size())
-      this._filterSelect.createOption(Common.UIString('All objects'));
+    this._filterSelect.createOption(Common.UIString('All objects'));
 
-    for (var i = this._filterSelect.size() - 1, n = list.length; i < n; ++i) {
+    for (var i = 0; i < list.length; ++i) {
       var title = list[i].title;
       if (!i)
         title = Common.UIString('Objects allocated before %s', title);

[alph, 2017/07/07 22:37:25]

nit: You can now move the custom 0-th item out of the loop, and start looping
with 1.

       else
         title = Common.UIString('Objects allocated between %s and %s', list[i - 1].title, title);
       this._filterSelect.createOption(title);
     }
   }
 
   _updateControls() {
     this._updatePerspectiveOptions();
     this._updateBaseOptions();
     this._updateFilterOptions();
   }
 
   /**
    * @param {!Common.Event} event
    */
   _onReceiveSnapshot(event) {
     this._updateControls();
+    var profile = event.data;
+    profile.addEventListener(Profiler.ProfileHeader.Events.ProfileTitleChanged, this._updateControls, this);
   }
 
   /**
    * @param {!Common.Event} event
    */
   _onProfileHeaderRemoved(event) {
     var profile = event.data;
     if (this._profile === profile) {
       this.detach();
       this._profile.profileType().removeEventListener(
           Profiler.HeapSnapshotProfileType.SnapshotReceived, this._onReceiveSnapshot, this);
       this._profile.profileType().removeEventListener(
           Profiler.ProfileType.Events.RemoveProfileHeader, this._onProfileHeaderRemoved, this);
+      this._profile.profileType().removeEventListener(

[alph, 2017/07/07 22:37:25]

The listener had been set on the profile instance, not the type.

Also you should be removing the listener for any profile header being removed
(so match the addEventListener), not just the one corresponding to the current
view.

+          Profiler.ProfileHeader.Events.ProfileTitleChanged, this._updateControls, this);
       this.dispose();
     } else {
       this._updateControls();
     }
   }
 
   dispose() {
     if (this._allocationStackView) {
       this._allocationStackView.clear();
       this._allocationDataGrid.dispose();
@@ skipping 1388 matching lines @@
           frame.line - 1, frame.column - 1);
       frameDiv.appendChild(urlElement);
     }
   }
 
   clear() {
     this.element.removeChildren();
     this._linkifier.reset();
   }
 };