WebUI: For cr-dialog, handle Enter keys in paper-inputs.

chrome/test/data/webui/cr_elements/cr_dialog_test.js

Index: chrome/test/data/webui/cr_elements/cr_dialog_test.js
diff --git a/chrome/test/data/webui/cr_elements/cr_dialog_test.js b/chrome/test/data/webui/cr_elements/cr_dialog_test.js
index 5e1f0ef3f52539ab242275b5a26a65c8dfb53c76..219bdadd67c07dc78a34df5e7814d5b4fe1e0fef 100644
--- a/chrome/test/data/webui/cr_elements/cr_dialog_test.js
+++ b/chrome/test/data/webui/cr_elements/cr_dialog_test.js
@@ -90,6 +90,41 @@ suite('cr-dialog', function() {
     assertTrue(clicked);
   });
 
+  test('enter keys from paper-inputs (only) are processed', function() {
+    document.body.innerHTML = `
+      <dialog is="cr-dialog">
+        <div class="title">title</div>
+        <div class="body">
+          <paper-input></paper-input>
+          <foobar></foobar>
+          <button class="action-button">active</button>
+        </div>
+      </dialog>`;
+
+    var dialog = document.body.querySelector('dialog');
+
+    var inputElement = document.body.querySelector('paper-input');
+    var otherElement = document.body.querySelector('foobar');
+    var actionButton = document.body.querySelector('.action-button');
+    assertTrue(!!inputElement);
+    assertTrue(!!otherElement);
+    assertTrue(!!actionButton);
+
+    // MockInteractions triggers event listeners synchronously.
+    var clickedCounter = 0;
+    actionButton.addEventListener('click', function() {
+      clickedCounter += 1;

[dpapad, 2017/04/05 21:34:45]

Nit (optional): clickedCounter++;

[tommycli, 2017/04/05 21:42:48]

Done.

+    });
+
+    MockInteractions.keyEventOn(
+        otherElement, 'keypress', 13, undefined, 'Enter');

[dpapad, 2017/04/05 21:34:45]

Nit (optional): Can we make a helper

function pressEnter(element) {
  MockInteractions.keyEventOn(element, 'keypress', 13, undefined, 'Enter');
}

and re-use it throughout this file (I see 5 occurrences currently).

[tommycli, 2017/04/05 21:42:48]

Done.

+    assertEquals(0, clickedCounter);
+
+    MockInteractions.keyEventOn(
+        inputElement, 'keypress', 13, undefined, 'Enter');
+    assertEquals(1, clickedCounter);
+  });
+
   test('focuses [autofocus] instead of title when present', function() {
     document.body.innerHTML = `
       <dialog is="cr-dialog">