Place frames under experiment

Author: sbuggay

front_end/core/host/UserMetrics.ts

@@ -985,10 +985,11 @@ export enum DevtoolsExperiments {
   'timeline-alternative-navigation' = 104,
   // 106 was historically used [https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6230097]
   // next experiment should be 107
+  'timeline-frames' = 108,
   /* eslint-enable @typescript-eslint/naming-convention */
 
   // Increment this when new experiments are added.
-  MAX_VALUE = 106,
+  MAX_VALUE = 108,
 }
 
 // Update DevToolsIssuesPanelIssueExpanded from tools/metrics/histograms/enums.xml if new enum is added.

front_end/core/root/Runtime.ts

@@ -332,6 +332,7 @@ export const enum ExperimentName {
   TIMELINE_DEBUG_MODE = 'timeline-debug-mode',
   TIMELINE_ENHANCED_TRACES = 'timeline-enhanced-traces',
   TIMELINE_COMPILED_SOURCES = 'timeline-compiled-sources',
+  TIMELINE_FRAMES = 'timeline-frames',
   TIMELINE_EXPERIMENTAL_INSIGHTS = 'timeline-experimental-insights',
   TIMELINE_DIM_UNRELATED_EVENTS = 'timeline-dim-unrelated-events',
   TIMELINE_ALTERNATIVE_NAVIGATION = 'timeline-alternative-navigation',

front_end/entrypoints/main/MainImpl.ts

@@ -301,6 +301,8 @@ export class MainImpl {
     Root.Runtime.experiments.register(
         Root.Runtime.ExperimentName.TIMELINE_DEBUG_MODE,
         'Performance panel: Enable debug mode (trace event details, etc)', true);
+    Root.Runtime.experiments.register(
+        Root.Runtime.ExperimentName.TIMELINE_FRAMES, 'Performance panel: Enable frames track', true);
 
     // Debugging
     Root.Runtime.experiments.register('instrumentation-breakpoints', 'Enable instrumentation breakpoints', true);

front_end/panels/timeline/TimelineFlameChartDataProvider.ts

@@ -608,7 +608,9 @@ export class TimelineFlameChartDataProvider extends Common.ObjectWrapper.ObjectW
     // In CPU Profiles the trace data will not have frames nor
     // screenshots, so we can keep this call as it will be a no-op in
     // these cases.
-    this.#appendFramesAndScreenshotsTrack();
+    if (Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.TIMELINE_FRAMES)) {
+      this.#appendFramesAndScreenshotsTrack();
+    }
 
     const weight = (track: {type?: string, forMainFrame?: boolean, appenderName?: TrackAppenderName}): number => {
       switch (track.appenderName) {

front_end/testing/EnvironmentHelpers.ts

@@ -128,6 +128,7 @@ const REGISTERED_EXPERIMENTS = [
   Root.Runtime.ExperimentName.TIMELINE_EXPERIMENTAL_INSIGHTS,
   Root.Runtime.ExperimentName.TIMELINE_DIM_UNRELATED_EVENTS,
   Root.Runtime.ExperimentName.TIMELINE_ALTERNATIVE_NAVIGATION,
+  Root.Runtime.ExperimentName.TIMELINE_FRAMES,
   Root.Runtime.ExperimentName.REACT_NATIVE_SPECIFIC_UI,
   Root.Runtime.ExperimentName.NOT_REACT_NATIVE_SPECIFIC_UI,
 ];

front_end/ui/visual_logging/KnownContextValues.ts

@@ -3495,6 +3495,7 @@ export const knownContextValues = new Set([
   'time',
   'timeline',
   'timeline-alternative-navigation',
+  'timeline-frames',
   'timeline-capture-layers-and-pictures',
   'timeline-capture-selector-stats',
   'timeline-compiled-sources',