DevTools: skip audio context selector empty list state with _items.replace

Problem:
When a web audio context change event occurs the "changed to" context is
first removed from the context selector list then added back.

If the list only contains 1 items then the list contents goes 1 -> 0 -> 1
and the event listener AudioContextSelector._onListItemReplaced will
intermediately disable the context menu during the change event when the
empty state list is reached.

This can cause side-effects and is extra cycles we don't need to spend.

Solution:
The UI.ListModel.replace method does the same operation without the intermediary
empty list state.

Change-Id: Ide76e2281c6c7224c22e77f3e7a5766fb2ef0a24
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1823730
Commit-Queue: John Emau <John.Emau@microsoft.com>
Reviewed-by: Yang Guo <yangguo@chromium.org>
Reviewed-by: Mandy Chen <mandy.chen@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#704856}

third_party/blink/renderer/devtools/front_end/web_audio/AudioContextSelector.js

@@ -61,8 +61,7 @@ WebAudio.AudioContextSelector = class extends Common.Object {
     const changedContext = /** @type {!Protocol.WebAudio.BaseAudioContext} */ (event.data);
     const contextIndex = this._items.findIndex(context => context.contextId === changedContext.contextId);
     if (contextIndex > -1) {
-      this._items.remove(contextIndex);
-      this._items.insert(contextIndex, changedContext);
+      this._items.replace(contextIndex, changedContext);
 
       // If the changed context is currently selected by user. Re-select it
       // because the actual element is replaced with a new one.

third_party/blink/web_tests/http/tests/devtools/webaudio/audio-context-selector-test-expected.txt

@@ -62,7 +62,6 @@ Selected Context: {
 
 Running: testOnListItemReplacedCalled
 _onListItemReplaced called with contexts (items) count: 1
-_onListItemReplaced called with contexts (items) count: 0
 _onListItemReplaced called with contexts (items) count: 1
 
 Number of contexts (items): 1