WebUI cr-toggle: Fix corner case of calling click() when disabled.

When disabled, calling click() (which simulates a 'click' event) should not
change the state of the toggle.

Bug: None
Cq-Include-Trybots: luci.chromium.try:closure_compilation
Change-Id: I2f1950c698fbc99abd7620d1573f592607f160e2
Reviewed-on: https://chromium-review.googlesource.com/1112719Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Demetrios Papadopoulos <dpapad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570144}

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

@@ -211,4 +211,20 @@ suite('cr-toggle', function() {
     triggerPointerDownMoveUpTapSequence(0 /* no pointermove */);
     assertChecked();
   });
+
+  // Test that the control works as expected when the click() method is called.
+  test('ToggleWhenWithClick', function() {
+    assertNotDisabled();
+    assertNotChecked();
+
+    // State should change because control is enabled.
+    toggle.click();
+    assertChecked();
+
+    // State should *not* change because control is disabled.
+    toggle.disabled = true;
+    assertDisabled();
+    toggle.click();
+    assertChecked();
+  });
 });

ui/webui/resources/cr_elements/cr_toggle/cr_toggle.js

@@ -137,6 +137,11 @@ Polymer({
     e.stopPropagation();
     e.preventDefault();
 
+    // Ignore case where 'click' handler is triggered while disabled. Can happen
+    // via calling the click() method.
+    if (this.disabled)
+      return;
+
     // User gesture has already been taken care of inside |pointermove|
     // handlers, Do nothing here.
     if (this.handledInPointerMove_)