Do not reset trace data when custom tracks setting changes

When the checkbox for the setting is clicked, we are calling
FlameChartDataProvider::reset, which as of [1] resets the trace data.
This is not the initially intended behavior as we only want to reset the
UI data. To fix this we simply call clearTimelineDataCache instead of
reset.

[1] https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6098009
Fixed: 391039190
Change-Id: I9987f00e6bfc2abfcd3d9c649fdc2f2b52b7f37e
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6185442
Reviewed-by: Jack Franklin <[email protected]>
Auto-Submit: Andres Olivares <[email protected]>
Commit-Queue: Jack Franklin <[email protected]>

Author: and-oli

front_end/panels/timeline/TimelineFlameChartView.ts

@@ -976,7 +976,7 @@ export class TimelineFlameChartView extends Common.ObjectWrapper.eventMixin<Even
   extensionDataVisibilityChanged(): void {
     this.reset();
     this.setupWindowTimes();
-    this.mainDataProvider.reset();
+    this.mainDataProvider.clearTimelineDataCache();
     this.mainDataProvider.timelineData(true);
     this.refreshMainFlameChart();
   }