Fix cursor disappearing in deep scans

Bug: 1100902
Change-Id: Ibf7537f2ec2084a3e4a03c33ab4c45ad5835e046
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2346914Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Dominique Fauteux-Chapleau <domfc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#797866}

content/browser/web_contents/web_contents_impl.cc

@@ -7849,6 +7849,10 @@ void WebContentsImpl::IsClipboardPasteAllowedWrapperCallback(
     ClipboardPasteAllowed allowed) {
   std::move(callback).Run(allowed);
   --suppress_unresponsive_renderer_count_;
+
+  // Focus |this| in case the paste was async and lost focus before this
+  // callback got called.
+  Focus();
 }
 
 bool WebContentsImpl::HasSeenRecentScreenOrientationChange() {