Revert "[Picture in Picture] Call parent function in OnGestureEvent."

This reverts commit e60d9aef.

Reason for revert: Causes the close button to receive gesture events even when it's not the target of the tap. This causes the PiP window to unexpectedly close.

Bug: 895773

Original change's description:
> [Picture in Picture] Call parent function in OnGestureEvent.
>
> Change-Id: I854654be22abd217c3f8ed557bc3fb9118c557c6
> Reviewed-on: https://chromium-review.googlesource.com/1192326
> Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
> Commit-Queue: apacible <apacible@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#586820}

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: I2f36d78713f0b811a0a2681e09284c394e146a5c
Reviewed-on: https://chromium-review.googlesource.com/c/1318397
Commit-Queue: Tommy Steimel <steimel@chromium.org>
Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607039}

chrome/browser/ui/views/overlay/overlay_window_views.cc

@@ -788,8 +788,6 @@ void OverlayWindowViews::OnGestureEvent(ui::GestureEvent* event) {
     TogglePlayPause();
     event->SetHandled();
   }
-
-  views::Widget::OnGestureEvent(event);
 }
 
 void OverlayWindowViews::ButtonPressed(views::Button* sender,