b=278599, focus doesn't switch to content area after clicking on bookmark from sidebar, r+a=mconnor

browser/components/bookmarks/content/bookmarksTree.xml

@@ -572,10 +572,6 @@
           }
           var browserTarget = whereToOpenLink(aEvent);
           BookmarksCommand.openBookmark(selection, browserTarget, this.db);
-          // give focus back to this; openBookmark/openLocation steals it and gives it
-          // to the browser content.  This is to make things like cut/copy/etc. behave sanely
-          // in the bookmarks sidebar.
-          this.focus();
         ]]></body>
       </method>