Hide duplicate management disclosure in about page

Settings page visual: http://screen/SmaWDcxWq2R
About page visual: http://screen/db8RQ9EbOS7


Bug: 954400
Change-Id: If9d79de0ef5c5eba39af1a5c108e9d056c0a3573
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1574440Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Commit-Queue: Yann Dago <ydago@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652413}

chrome/browser/resources/settings/settings_main/settings_main.html

@@ -57,7 +57,8 @@
       <div>$i18nRaw{searchNoResultsHelp}</div>
     </div>
     <template is="dom-if"
-        if="[[showManagedHeader_(inSearchMode_, showingSubpage_)]]">
+        if="[[showManagedHeader_(inSearchMode_, showingSubpage_,
+        showPages_.about)]]">
       <managed-footnote></managed-footnote>
     </template>
     <template is="dom-if" if="[[showPages_.settings]]">

chrome/browser/resources/settings/settings_main/settings_main.js

@@ -237,6 +237,7 @@ Polymer({
    * @private
    */
   showManagedHeader_: function() {
-    return !this.inSearchMode_ && !this.showingSubpage_;
+    return !this.inSearchMode_ && !this.showingSubpage_ &&
+        !this.showPages_.about;
   },
 });

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

@@ -111,7 +111,8 @@ cr.define('settings_main_page', function() {
 
     function showManagedHeader() {
       return settingsMain.showManagedHeader_(
-          settingsMain.inSearchMode_, settingsMain.showingSubpage_);
+          settingsMain.inSearchMode_, settingsMain.showingSubpage_,
+          settingsMain.showPages_.about);
     }
 
     test('managed header hides when searching', function() {
@@ -143,6 +144,15 @@ cr.define('settings_main_page', function() {
       assertFalse(showManagedHeader());
     });
 
+    test('managed header hides when showing about page', function() {
+      Polymer.dom.flush();
+
+      assertTrue(showManagedHeader());
+      settings.navigateTo(settings.routes.ABOUT);
+
+      assertFalse(showManagedHeader());
+    });
+
     /** @return {!HTMLElement} */
     function getToggleContainer() {
       const page = settingsMain.$$('settings-basic-page');