[ProfilePicker]: Hide Ask on startup for single profile users.

Fixed: 1123093
Change-Id: I09935ef9c9ff0bb4104d887c0314653327faced2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2382590
Auto-Submit: Monica Basta <msalama@chromium.org>
Reviewed-by: David Roger <droger@chromium.org>
Commit-Queue: David Roger <droger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802954}

chrome/browser/resources/signin/profile_picker/profile_picker_main_view.html

@@ -118,6 +118,10 @@
     padding-inline-start: 5px;
   }
 
+  cr-checkbox[hidden] {
+    display: none;
+  }
+
   @media (prefers-color-scheme: dark) {
     #leftBanner {
       background: url(images/dark_mode_left_banner_image.svg);
@@ -143,16 +147,17 @@
   }
 </style>
 
-<div id="leftBanner" class="banner"></div>
-<div class="title-container">
+<template is="dom-if" if="[[profilesList_]]">
+  <div id="leftBanner" class="banner"></div>
+  <div class="title-container">
     <img id="product-logo" on-click="onProductLogoTap_"
         srcset="chrome://theme/current-channel-logo@1x 1x,
                 chrome://theme/current-channel-logo@2x 2x"
         role="presentation">
     <h2>$i18n{mainViewTitle}</h2>
     <h3>$i18n{mainViewSubtitle}</h3>
-</div>
-<div id="wrapper">
+  </div>
+  <div id="wrapper">
     <div class="profiles-container">
       <template is="dom-repeat"
           hidden="[[!profilesList_]]" items="[[profilesList_]]">
@@ -169,16 +174,18 @@
         <div class="profile-card-info"></div>
       </div>
     </div>
-</div>
-<div id="rightBanner" class="banner"></div>
+  </div>
+  <div id="rightBanner" class="banner"></div>
 
-<div class="footer">
+  <div class="footer">
     <cr-button id="browseAsGuestButton" on-click="onLaunchGuestProfileClick_">
       <iron-icon icon="profiles:account-circle"></iron-icon>
       <div>$i18n{browseAsGuestButton}</div>
     </cr-button>
     <cr-checkbox checked="{{askOnStartup_}}"
-      on-change="onAskOnStartupChangedByUser_">
+        on-change="onAskOnStartupChangedByUser_"
+        hidden="[[shouldHideAskOnStartup_(profilesList_.length)]]">
       $i18n{askOnStartupCheckboxText}
     </cr-checkbox>
-</div>
+  </div>
+</template>

chrome/browser/resources/signin/profile_picker/profile_picker_main_view.js

@@ -125,4 +125,12 @@ Polymer({
       }
     }
   },
+
+  /**
+   * @return boolean
+   * @private
+   */
+  shouldHideAskOnStartup_() {
+    return !this.profilesList_ || (this.profilesList_.length < 2);
+  },
 });