Polymer: Remove unused app-layout element

third_party/polymer/v1_0/components-chromium/app-layout/app-scroll-effects/effects/fade-background-extracted.js

-/**
-   * Upon scrolling past a threshold, fade in the rear background layer and fade out the front
-   * background layer (opacity CSS transitioned over time).
-   *
-   *
-   */
-  Polymer.AppLayout.registerEffect('fade-background', {
-    /** @this Polymer.AppLayout.ElementWithBackground */
-    setUp: function setUp(config) {
-      var fx = {};
-      var duration = config.duration || '0.5s';
-      fx.backgroundFrontLayer = this._getDOMRef('backgroundFrontLayer');
-      fx.backgroundRearLayer = this._getDOMRef('backgroundRearLayer');
-      fx.backgroundFrontLayer.style.willChange = 'opacity';
-      fx.backgroundFrontLayer.style.webkitTransform = 'translateZ(0)';
-      fx.backgroundFrontLayer.style.transitionProperty = 'opacity';
-      fx.backgroundFrontLayer.style.transitionDuration = duration;
-      fx.backgroundRearLayer.style.willChange = 'opacity';
-      fx.backgroundRearLayer.style.webkitTransform = 'translateZ(0)';
-      fx.backgroundRearLayer.style.transitionProperty = 'opacity';
-      fx.backgroundRearLayer.style.transitionDuration = duration;
-      this._fxFadeBackground = fx;
-    },
-    /** @this Polymer.AppLayout.ElementWithBackground */
-    run: function run(p, y) {
-      var fx = this._fxFadeBackground;
-      if (p >= 1) {
-        fx.backgroundFrontLayer.style.opacity = 0;
-        fx.backgroundRearLayer.style.opacity = 1;
-      } else {
-        fx.backgroundFrontLayer.style.opacity = 1;
-        fx.backgroundRearLayer.style.opacity = 0;
-      }
-    },
-    /** @this Polymer.AppLayout.ElementWithBackground */
-    tearDown: function tearDown() {
-      delete this._fxFadeBackground;
-    }
-  });