allow configuring restore-focus-on-close (#94)

* allow configuring restore-focus-on-close

* add doc comment

* test that restoreFocusOnClose propagates to dropdown

* shave some indent and re-order property after merging

* the OCD is taking hold

* srsly

paper-menu-button.html

@@ -124,7 +124,7 @@
       no-animations="[[noAnimations]]"
       focus-target="[[_dropdownContent]]"
       allow-outside-scroll="[[allowOutsideScroll]]"
-      restore-focus-on-close
+      restore-focus-on-close="[[restoreFocusOnClose]]"
       on-iron-overlay-canceled="__onIronOverlayCanceled">
       <div class="dropdown-content">
         <content id="content" select=".dropdown-content"></content>
@@ -330,6 +330,14 @@
             value: false
           },
 
+          /**
+           * Whether focus should be restored to the button when the menu closes.
+           */
+          restoreFocusOnClose: {
+            type: Boolean,
+            value: true
+          },
+
           /**
            * This is the element intended to be bound as the focus target
            * for the `iron-dropdown` contained by `paper-menu-button`.

test/paper-menu-button.html

@@ -131,6 +131,13 @@
         expect(menuButton.$.dropdown.allowOutsideScroll).to.be.equal(true);
       });
 
+      test('restoreFocusOnClose propagates to <iron-dropdown>', function() {
+        menuButton.restoreFocusOnClose = false;
+        expect(menuButton.$.dropdown.restoreFocusOnClose).to.be.equal(false);
+        menuButton.restoreFocusOnClose = true;
+        expect(menuButton.$.dropdown.restoreFocusOnClose).to.be.equal(true);
+      });
+
     });
 
     suite('when there are two buttons', function() {