Import Polymer 0.8 and several key elements.

third_party/polymer/v0_8/components-chromium/paper-behaviors/paper-button-behavior-extracted.js

+
+
+  Polymer.PaperButtonElevation = {
+
+    properties: {
+
+      _elevation: {
+        type: Number
+      }
+
+    },
+
+    _calculateElevation: function() {
+      var e = 1;
+      if (this.disabled || !this.raised) {
+        e = 0;
+      } else if (this.active || this.pressed) {
+        e = 2;
+      } else if (this.focused) {
+        e = 3;
+      }
+      this._elevation = e;
+    }
+
+  };
+
+  Polymer.PaperButtonBehavior = [
+    Polymer.IronControlState,
+    Polymer.IronButtonState,
+    Polymer.PaperButtonElevation
+  ];
+