Geolocation::HasPendingActivity should check watchers_ as well

This is a follow-up CL for https://chromium-review.googlesource.com/892557.
GeoNotifiers are in one_shots_ and watchers_. I forgot to support watchers_
in that CL.

Bug: 792604
Change-Id: I1421e14311de6c965cffc038892cfabdb63a4dbb
Reviewed-on: https://chromium-review.googlesource.com/894924Reviewed-by: Yuki Shiino <yukishiino@chromium.org>
Commit-Queue: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#533210}

third_party/WebKit/Source/modules/geolocation/Geolocation.cpp

@@ -526,7 +526,8 @@ void Geolocation::PageVisibilityChanged() {
 }
 
 bool Geolocation::HasPendingActivity() const {
-  return !one_shots_.IsEmpty() || !one_shots_being_invoked_.IsEmpty();
+  return !one_shots_.IsEmpty() || !one_shots_being_invoked_.IsEmpty() ||
+         !watchers_.IsEmpty() || !watchers_being_invoked_.IsEmpty();
 }
 
 void Geolocation::OnGeolocationConnectionError() {