[SendTabToSelf] Reset slide animation if icon is not visible.

This fixes the bug where the STTS icon overlaps with the bookmark icon when the animation gets interrupted by reloading the page.

Bug: 1085708
Change-Id: I1296d282afb2a8e5e6ec1500db9828856701be57
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2217768Reviewed-by: Kristi Park <kristipark@chromium.org>
Commit-Queue: Sophey Dong <sophey@chromium.org>
Cr-Commit-Position: refs/heads/master@{#772333}

chrome/browser/ui/views/send_tab_to_self/send_tab_to_self_icon_view.cc

@@ -143,6 +143,9 @@ void SendTabToSelfIconView::AnimationEnded(const gfx::Animation* animation) {
 }
 
 void SendTabToSelfIconView::UpdateOpacity() {
+  if (!GetVisible()) {
+    ResetSlideAnimation(false);
+  }
   if (!IsShrinking()) {
     DestroyLayer();
     SetTextSubpixelRenderingEnabled(true);