[RPP] Prevent double-draw during dimming

The first dimming from hovering in a table was double-drawing the
flame graph due to the "disabled" state of the 3p-dimming setting
calling "refreshDimming" again.

We don't actually need to disable the setting, so deleting that line
fixes this.

https://trace.cafe/t/VbetOBZ0OP

Bug: 40278532
Change-Id: I8fc16f2025861d1adc546740a309287c0a43caeb
Reviewed-on: https://chromium-review.googlesource.com/c/devtools/devtools-frontend/+/6219691
Auto-Submit: Connor Clark <[email protected]>
Commit-Queue: Paul Irish <[email protected]>
Reviewed-by: Paul Irish <[email protected]>

Author: Connor Clark

front_end/panels/timeline/TimelinePanel.ts

@@ -738,18 +738,13 @@ export class TimelinePanel extends UI.Panel.Panel implements Client, TimelineMod
   /**
    * This "disables" the 3P checkbox in the toolbar.
    * Disabling here does a couple of things:
-   * 1) updates the setting to "disabled"
-   * 2) makes the checkbox dimmed and unclickable
-   * 3) gives the checkbox UI an indeterminate state
-   * Only make the change if it's different to avoid an infinite loop
+   * 1) makes the checkbox dimmed and unclickable
+   * 2) gives the checkbox UI an indeterminate state
    */
   set3PCheckboxDisabled(disabled: boolean): void {
     if (Root.Runtime.experiments.isEnabled(Root.Runtime.ExperimentName.TIMELINE_DIM_UNRELATED_EVENTS)) {
-      if (this.#thirdPartyCheckbox?.inputElement.disabled !== disabled) {
-        this.#thirdPartyCheckbox?.applyEnabledState(!disabled);
-        this.#thirdPartyCheckbox?.setIndeterminate(disabled);
-        this.#dimThirdPartiesSetting?.setDisabled(disabled);
-      }
+      this.#thirdPartyCheckbox?.applyEnabledState(!disabled);
+      this.#thirdPartyCheckbox?.setIndeterminate(disabled);
     }
   }