[CrOS MultiDevice] Block false Settings error from ambiguous listener.

The settings-multidevice-setup-page listens for the event 'close'
as a proxy for the password prompt being confirmed. However, the
event type 'close' is ubiquitous to cr-dialog so it also fires when
the forget device dialog is closed on the subpage, which causes the
assertion "assert(this.featureToBeEnabledOnceAuthenticated_ !== null)"
in SettingsMultidevicePageElement.onPasswordPromptDialogClose() to
fail.

This CL only calls onPasswordPromptDialogClose_ if the close event came
from the MultiDevice page's password prompt and stops the event's
propagation.

Bug: 887160
Change-Id: I5740061c8f9e08ee5ba9e8d99862bcec6b0a6677
Reviewed-on: https://chromium-review.googlesource.com/1235321
Commit-Queue: Jordy Greenblatt <jordynass@chromium.org>
Reviewed-by: Kyle Horimoto <khorimoto@chromium.org>
Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Cr-Commit-Position: refs/heads/master@{#592908}

chrome/browser/resources/settings/multidevice_page/multidevice_page.html

@@ -42,7 +42,7 @@
           <div class$=
               "[[getMultiDeviceItemLabelBlockCssClass_(pageContentData)]]">
             <div id="multidevice-label">[[getLabelText_(pageContentData)]]</div>
-            <div id="mutltideviceSubLabel" class="secondary"
+            <div id="multideviceSubLabel" class="secondary"
                 inner-h-t-m-l="[[getSubLabelInnerHtml_(pageContentData)]]">
             </div>
           </div>
@@ -64,7 +64,7 @@
                 restamp>
               <paper-icon-button-light class="subpage-arrow">
                 <button aria-labelledby="multidevice-label"
-                    aria-describedby="mutltideviceSubLabel"></button>
+                    aria-describedby="multideviceSubLabel"></button>
               </paper-icon-button-light>
             </template>
             <div class="separator"></div>
@@ -97,7 +97,7 @@
       </template>
     </settings-animated-pages>
     <template is="dom-if" if="[[showPasswordPromptDialog_]]" restamp>
-      <settings-password-prompt-dialog id="passwordPrompt">
+      <settings-password-prompt-dialog id="multidevicePasswordPrompt">
       </settings-password-prompt-dialog>
     </template>
   </template>

chrome/browser/resources/settings/multidevice_page/multidevice_page.js

@@ -63,7 +63,7 @@ Polymer({
 
   listeners: {
     'auth-token-changed': 'onAuthTokenChanged_',
-    'close': 'onPasswordPromptDialogClose_',
+    'close': 'onDialogClose_',
     'feature-toggle-clicked': 'onFeatureToggleClicked_',
     'forget-device-requested': 'onForgetDeviceRequested_',
   },
@@ -204,6 +204,12 @@ Polymer({
     this.showPasswordPromptDialog_ = true;
   },
 
+  onDialogClose_: function(event) {
+    event.stopPropagation();
+    if (event.path.some(element => element.id === 'multidevicePasswordPrompt'))
+      this.onPasswordPromptDialogClose_();
+  },
+
   /** @private */
   onPasswordPromptDialogClose_: function() {
     // The password prompt should only be shown when there is a feature waiting

chrome/test/data/webui/settings/multidevice_page_tests.js

@@ -87,7 +87,8 @@ suite('Multidevice', function() {
       assertTrue(multidevicePage.showPasswordPromptDialog_);
       // Simulate the user entering a valid password, then closing the dialog.
       multidevicePage.fire('auth-token-changed', {value: 'validAuthToken'});
-      multidevicePage.fire('close');
+      // Simulate closing the password prompt dialog
+      multidevicePage.$$('#multidevicePasswordPrompt').fire('close');
       Polymer.dom.flush();
     } else {
       assertFalse(multidevicePage.showPasswordPromptDialog_);