Polymer alters the results of scoped queries in querySelectorAll

[hubgit]

If the following is run in Chrome's JavaScript console on https://google.com/ (i.e. a page without Polymer present), it returns 18 matches from both selectors:

console.log(document.querySelectorAll('div').length + ' unscoped nodes');
console.log(document.querySelectorAll(':scope div').length + ' scoped nodes');

If the same code is run in the JavaScript console on http://www.polymer-project.org/ (i.e. a page where Polymer is included), it returns 0 results for the second, scoped selector.

Adding :scope to selectors is important when selecting descendants of a specific DOM element, so it's problematic that this breaks when Polymer is present.

[hubgit]

Filed in polymer/ShadowDOM instead.