[CrOS Settings] Disable 'confirm' button when password is being checked.

Currently, the confirm button is not disabled while the password is being
checked,serving a confusing experience as users can repeatedly hit the confirm
button without a visual ack that the password is being checked.  This CL
disables the confirm button while the password is being checked.

Bug: 999475
Change-Id: I907017dd1f7bfdf4cff318b0621d730b113200bd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1888150
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#710577}

chrome/browser/resources/settings/controls/password_prompt_dialog.html

@@ -39,7 +39,8 @@
         </cr-button>
 
         <cr-button id="confirmButton" class="action-button"
-            disabled$="[[!isConfirmEnabled_(inputValue_, passwordInvalid_)]]"
+            disabled$="[[!isConfirmEnabled_(inputValue_, passwordInvalid_,
+                waitingForPasswordCheck_)]]"
             on-click="submitPassword_">
           $i18n{confirm}
         </cr-button>

chrome/browser/resources/settings/controls/password_prompt_dialog.js

@@ -71,6 +71,12 @@ Polymer({
      * @type {QuickUnlockPrivate}
      */
     quickUnlockPrivate: {type: Object, value: chrome.quickUnlockPrivate},
+
+    /** @private {boolean} */
+    waitingForPasswordCheck_: {
+      type: Boolean,
+      value: false,
+    },
   },
 
   /** @return {!CrInputElement} */
@@ -109,6 +115,7 @@ Polymer({
    * @private
    */
   submitPassword_: function() {
+    this.waitingForPasswordCheck_ = true;
     clearTimeout(this.clearAccountPasswordTimeoutId_);
 
     const password = this.passwordInput.value;
@@ -116,10 +123,12 @@ Polymer({
     // Do not submit/show an error in this case.
     if (!password) {
       this.passwordInvalid_ = false;
+      this.waitingForPasswordCheck_ = false;
       return;
     }
 
     this.quickUnlockPrivate.getAuthToken(password, (tokenInfo) => {
+      this.waitingForPasswordCheck_ = false;
       if (chrome.runtime.lastError) {
         this.passwordInvalid_ = true;
         // Select the whole password if user entered an incorrect password.
@@ -154,7 +163,8 @@ Polymer({
 
   /** @private */
   isConfirmEnabled_: function() {
-    return !this.passwordInvalid_ && this.inputValue_;
+    return !this.waitingForPasswordCheck_ && !this.passwordInvalid_ &&
+        this.inputValue_;
   },
 });
 })();