From c04e7a1f81063d8f49602a5e1f3d492bf042f512 Mon Sep 17 00:00:00 2001
From: Alex Hunt <hello@alexhunt.dev>
Date: Wed, 24 Sep 2025 17:33:24 +0100
Subject: [PATCH] Disable Perf Insights subpanel, collapse sidebar by default

---
 front_end/panels/timeline/TimelinePanel.ts     |  6 +++++-
 .../panels/timeline/components/Sidebar.ts      | 18 ++++++++++++------
 2 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/front_end/panels/timeline/TimelinePanel.ts b/front_end/panels/timeline/TimelinePanel.ts
index 2ee9053cda2..07e01215639 100644
--- a/front_end/panels/timeline/TimelinePanel.ts
+++ b/front_end/panels/timeline/TimelinePanel.ts
@@ -772,7 +772,7 @@ export class TimelinePanel extends UI.Panel.Panel implements Client, TimelineMod
   #setActiveInsight(insight: TimelineComponents.Sidebar.ActiveInsight|null): void {
     // When an insight is selected, ensure that the 3P checkbox is disabled
     // to avoid dimming interference.
-    if (insight) {
+    if (insight && !Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.REACT_NATIVE_SPECIFIC_UI)) {
       this.#splitWidget.showBoth();
     }
     this.#sideBar.setActiveInsight(insight);
@@ -2185,6 +2185,10 @@ export class TimelinePanel extends UI.Panel.Panel implements Client, TimelineMod
       // Used in interaction tests & screenshot tests.
       return;
     }
+    // [RN] Keep sidebar collapsed by default
+    if (Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.REACT_NATIVE_SPECIFIC_UI)) {
+      return;
+    }
     const needToRestore = this.#restoreSidebarVisibilityOnTraceLoad;
     const userHasSeenSidebar = this.#sideBar.userHasOpenedSidebarOnce();
 
diff --git a/front_end/panels/timeline/components/Sidebar.ts b/front_end/panels/timeline/components/Sidebar.ts
index 4f2212aaa0e..c6b776c5dfa 100644
--- a/front_end/panels/timeline/components/Sidebar.ts
+++ b/front_end/panels/timeline/components/Sidebar.ts
@@ -3,6 +3,7 @@
 // found in the LICENSE file.
 
 import * as Common from '../../../core/common/common.js';
+import * as Root from '../../../core/root/root.js';
 import type * as Trace from '../../../models/trace/trace.js';
 import * as UI from '../../../ui/legacy/legacy.js';
 
@@ -68,16 +69,21 @@ export class SidebarWidget extends UI.Widget.VBox {
   constructor() {
     super();
     this.setMinimumSize(MIN_SIDEBAR_WIDTH_PX, 0);
-    this.#tabbedPane.appendTab(
-        SidebarTabs.INSIGHTS, 'Insights', this.#insightsView, undefined, undefined, false, false, 0,
-        'timeline.insights-tab');
+
+    // [RN] Disable Insights tab
+    const showInsightsTab = !Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.REACT_NATIVE_SPECIFIC_UI);
+
+    if (showInsightsTab) {
+      this.#tabbedPane.appendTab(
+          SidebarTabs.INSIGHTS, 'Insights', this.#insightsView, undefined, undefined, false, false, 0,
+          'timeline.insights-tab');
+    }
+
     this.#tabbedPane.appendTab(
         SidebarTabs.ANNOTATIONS, 'Annotations', this.#annotationsView, undefined, undefined, false, false, 1,
         'timeline.annotations-tab');
 
-    // Default the selected tab to Insights. In wasShown() we will change this
-    // if this is a trace that has no insights.
-    this.#tabbedPane.selectTab(SidebarTabs.INSIGHTS);
+    this.#tabbedPane.selectTab(showInsightsTab ? SidebarTabs.INSIGHTS : SidebarTabs.ANNOTATIONS);
   }
 
   override wasShown(): void {