[ios] remove comment in scene controller

Change-Id: I86625fa583c7b21b665bc2e19fc0b9e4b18a282c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2253745Reviewed-by: David Jean <djean@chromium.org>
Reviewed-by: edchin <edchin@chromium.org>
Auto-Submit: David Jean <djean@chromium.org>
Commit-Queue: edchin <edchin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#781148}

ios/chrome/browser/ui/main/scene_controller.mm

@@ -376,8 +376,6 @@ const char kMultiWindowOpenInNewWindowHistogram[] =
   if (sceneState.currentOrigin != WindowActivityRestoredOrigin) {
     if (IsMultiwindowSupported()) {
       if (@available(iOS 13, *)) {
-        // int origin =
-        //    static_cast<int>(sceneState.currentOrigin);
         base::UmaHistogramEnumeration(kMultiWindowOpenInNewWindowHistogram,
                                       sceneState.currentOrigin);
       }