Update "What's New in DevTools 128"

microsoft-edge/devtools-guide-chromium/evaluate-performance/selector-stats.md

@@ -10,6 +10,8 @@ ms.date: 05/15/2024
 ---
 # Analyze CSS selector performance during Recalculate Style events
 
+When your webpage has long-running **Recalculate Style** events, to identify which of your CSS selectors are taking up the most time and resulting in slow performance, use the **Selector Stats** tab in the **Performance** tool.  The **Selector Stats** tab provides statistics about the CSS rule selectors that were involved in one or more **Recalculate Style** events within a performance recording.
+
 The **Performance** tool highlights each long-running task with a red triangle in the upper right corner, to indicate work on the main thread that takes a long time to run and has slow performance:
 
 ![Long-Running Task indicators for events on the main thread with slow performance](./selector-stats-images/long-running-task.png)
@@ -24,10 +26,6 @@ CSS styles need to be recalculated whenever the applicability of CSS rules may h
 * When an element's attributes are changed, such as the value of a `class` or `id` attribute.
 * When user input occurs, such as a mouse move or a change of which element in a webpage has focus, which can affect `:hover` rules.
 
-When you have long-running **Recalculate Style** events, you can use the **Selector Stats** tab to understand which of your CSS selectors are taking up the most time and resulting in slow performance.
-
-The **Selector Stats** tab provides statistics about the CSS rule selectors that were involved in one or more **Recalculate Style** events within a performance recording.
-
 
 <!-- ====================================================================== -->
 ## Record a performance trace with Selector Stats enabled

microsoft-edge/devtools-guide-chromium/experimental-features/index.md

@@ -207,7 +207,8 @@ Status:
 
 <!-- ====================================================================== -->
 ## Show option to expose internals in heap snapshots
-<!-- checkbox has no (?) link pointing to this anchor wording -->
+<!-- checkbox has no (?) link pointing to this anchor wording
+[Heap snapshot improvements](../whats-new/2024/08/devtools-128.md#heap-snapshot-improvements) in _What's New in DevTools (Microsoft Edge 128)_ links to here -->
 
 _new as of Microsoft Edge 105_
 
@@ -575,9 +576,7 @@ See also:
 * [Performance recording event reference](../evaluate-performance/performance-reference.md)
 * [postMessage Trace Events demo (rendered)](https://microsoftedge.github.io/Demos/devtools-postmessage-perf-timeline/)
 * [postMessage Trace Events demo (source code)](https://github.com/MicrosoftEdge/Demos/tree/main/devtools-postmessage-perf-timeline)
-<!--
-* [postMessage events are distinguished from other timeline events](https://review.learn.microsoft.com/en-us/microsoft-edge/devtools-guide-chromium/whats-new/2024/04/devtools-124?branch=pr-en-us-3129#postmessage-events-are-distinguished-from-other-timeline-events) in _What's New in DevTools (Microsoft Edge 124)_.
--->
+* [postMessage events and handlers are distinguished from other events](../whats-new/2024/04/devtools-124.md#postmessage-events-and-handlers-are-distinguished-from-other-events) in _What's New in DevTools (Microsoft Edge 124)_.
 
 Status:
 * This checkbox is present in Microsoft Edge Canary 129.

microsoft-edge/devtools-guide-chromium/whats-new/2024/08/devtools-128.md

@@ -14,11 +14,11 @@ ms.date: 08/22/2024
 
 
 <!-- ====================================================================== -->
-## Updated labels for selector stats
+## Updated labels for CSS selector stats
 
 <!-- Subtitle: Use the "Enable CSS selector stats" setting instead of the "Enable advanced paint instrumentation (slow)" to capture CSS selector statistics for Recalculate Style events -->
 
-In the **Performance** tool, the duplicate **Selector Stats** label has been removed from the `Recalculate Style` event details.  Selector stats can be enabled by using the dedicated setting for it.
+In the **Performance** tool, the duplicate **Selector Stats** label has been removed from the `Recalculate Style` event details.  Selector stats can be enabled by using the dedicated setting<!-- todo: what is the ui path? eg: the Foo checkbox --> for it.
 
 Also, the **Enable advanced rendering instrumentation (slow)** setting has been renamed back to **Enable advanced paint instrumentation (slow)**.  Previously, this setting was used for both paint instrumentation and selector stats.  This setting label has been updated because there's now a dedicated setting for selector stats.
 
@@ -30,6 +30,9 @@ After:
 
 ![New selector stats labels](./devtools-128-images/new-selector-stats.png)
 
+See also:
+* [Analyze CSS selector performance during Recalculate Style events](../../../evaluate-performance/selector-stats.md)
+
 
 <!-- ====================================================================== -->
 ## Fixed whitespace in Activity Bar right-click menus
@@ -45,6 +48,36 @@ The top of each context menu now shows the title again:
 ![New context menu header](./devtools-128-images/header-title.png)
 
 
+<!-- ====================================================================== -->
+## Heap snapshot improvements
+
+<!-- Subtitle: Heap snapshots are generated faster, HTML elements are grouped by tag name, shallow sizes show fewer internal objects, and numeric values are always shown. -->
+
+In the **Memory** tool, there are several improvements for heap snapshots:
+
+* Generating heap snapshots is now faster.
+
+* HTML elements are grouped by tag name.<!-- todo: by element name? -->
+
+* Shallow sizes now match JavaScript semantics better, by showing fewer internal objects, unless the **Expose internals (includes additional implementation-specific details)** setting is enabled<!--todo: checkbox is selected?  where/what is this UI control?  not found after turned experiment on, and then created snapshot --> when the [Show option to expose internals in heap snapshots](../../../experimental-features/index.md#show-option-to-expose-internals-in-heap-snapshots) experiment is turned on.
+
+* The **Include numerical values in capture** setting<!-- todo: where was this setting in the UI?  was it a checkbox? --> has been removed, and heap snapshots now always show numeric values.
+
+See also:
+* [Record heap snapshots using the Memory tool](../../../memory-problems/heap-snapshots.md)
+
+
+<!-- ====================================================================== -->
+## View WebSocket message activities in the Performance tool
+
+<!-- Subtitle: WebSocket activities were added to the Network track in the Performance tool to help correlate JavaScript activity with WebSocket messages. -->
+
+WebSocket activities have been added to the **Network** track in the **Performance** tool, to help correlate JavaScript activity with WebSocket messages.  This can help identify whether latency issues are coming from the client's parsing of a message, or from the server's response.
+
+See also:
+* [Introduction to the Performance tool](../../../evaluate-performance/index.md)
+
+
 <!-- ====================================================================== -->
 ## Announcements from the Chromium project
 

microsoft-edge/toc.yml

@@ -633,7 +633,7 @@
 
                 - name: Analyze CSS selector performance during Recalculate Style events
                   href: devtools-guide-chromium/evaluate-performance/selector-stats.md
-                  displayName: Performance tool
+                  displayName: Performance tool, CSS selector stats
 # Performance monitor tool ----------------------------------------------------
             - name: Performance monitor tool
               items: