MD Settings: shrink overscroll on resize

Recalculate overscroll when shrinking the page, so we don't end up with
a scrollbar for the empty space below us.

BUG=none
R=dschuyler@chromium.org
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:closure_compilation

Review-Url: https://codereview.chromium.org/2382603002
Cr-Commit-Position: refs/heads/master@{#422684}

chrome/browser/resources/settings/settings_main/settings_main.js

@@ -103,6 +103,7 @@ Polymer({
   overscrollChanged_: function() {
     if (!this.overscroll_ && this.boundScroll_) {
       this.offsetParent.removeEventListener('scroll', this.boundScroll_);
+      window.removeEventListener('resize', this.boundScroll_);
       this.boundScroll_ = null;
     } else if (this.overscroll_ && !this.boundScroll_) {
       this.boundScroll_ = function() {
@@ -110,6 +111,7 @@ Polymer({
           this.setOverscroll_(0);
       }.bind(this);
       this.offsetParent.addEventListener('scroll', this.boundScroll_);
+      window.addEventListener('resize', this.boundScroll_);
     }
   },