[Picture in Picture] Hide controls 2.5s after keyboard interaction.

Previously, only gestures (i.e. tap) would trigger the controls to hide
after a certain period of time. This change also adds this behavior for
keyboard interaction to avoid forcing the user to blur the window to
hide the controls.

Bug: 879294
Change-Id: I697099c317c05a8e206acfab24848b8fd0ce149d
Reviewed-on: https://chromium-review.googlesource.com/1197408Reviewed-by: CJ DiMeglio <lethalantidote@chromium.org>
Commit-Queue: apacible <apacible@chromium.org>
Cr-Commit-Position: refs/heads/master@{#587817}

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

@@ -600,6 +600,10 @@ void OverlayWindowViews::OnNativeWidgetBeginUserBoundsChange() {
 }
 
 void OverlayWindowViews::OnKeyEvent(ui::KeyEvent* event) {
+  // Every time a user uses a keyboard to interact on the window, restart the
+  // timer to automatically hide the controls.
+  hide_controls_timer_.Reset();
+
   // Any keystroke will make the controls visible, if not already. The Tab key
   // needs to be handled separately.
   // If the controls are already visible, this is a no-op.