SettingsSplit: Add route for newly branched 'file' page

In my fix [1] for our bug to change the OS Settings 'downloads' section
to a naming pattern based around the term 'files' to match UX specs
[2], I didn't add a separate route for files for OS-Settings. This CL
adds that section in. I manually ensured that clicking 'Files' item in
os-settings-menu scrolls to the 'Files' section [3].

[1] https://chromium-review.googlesource.com/c/chromium/src/+/1696180
[2] http://crbug.com/978648
[3] http://screen/9QpZtnw8TS0

Bug: 986466
Change-Id: I7d255a41015b307c674bf231878dffa72066ca5a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1713909Reviewed-by: Hector Carmona <hcarmona@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Commit-Queue: Jordy Greenblatt <jordynass@chromium.org>
Cr-Commit-Position: refs/heads/master@{#679809}

chrome/browser/resources/settings/chromeos/os_settings_menu/os_settings_menu.html

@@ -84,8 +84,8 @@
         --ink-color: var(--menu-text-color);
         align-items: center;
         background: none;
-        border-radius: initial;
         border: none;
+        border-radius: initial;
         box-shadow: none;
         color: var(--menu-text-color);
         display: flex;
@@ -230,10 +230,10 @@
               $i18n{osLanguagesPageTitle}
             </div>
           </a>
-          <a href="/downloads">
+          <a href="/files">
             <div class="item">
               <iron-icon icon="cr:file-download"></iron-icon>
-              $i18n{downloadsPageTitle}
+              $i18n{filesPageTitle}
             </div>
           </a>
           <a href="/printing">

chrome/browser/resources/settings/route.js

@@ -43,6 +43,7 @@
  *   EDIT_DICTIONARY: (undefined|!settings.Route),
  *   EXTERNAL_STORAGE_PREFERENCES: (undefined|!settings.Route),
  *   FINGERPRINT: (undefined|!settings.Route),
+ *   FILES: (undefined|!settings.Route),
  *   FONTS: (undefined|!settings.Route),
  *   GOOGLE_ASSISTANT: (undefined|!settings.Route),
  *   IMPORT_DATA: (undefined|!settings.Route),
@@ -257,12 +258,6 @@ cr.define('settings', function() {
     r.SMART_LOCK =
         r.MULTIDEVICE_FEATURES.createChild('/multidevice/features/smartLock');
 
-    // TODO(hsuregan): Remove once this file is forked.
-    if (loadTimeData.getBoolean('isOSSettings')) {
-      r.PERSONALIZATION =
-          r.BASIC.createSection('/personalization', 'personalization');
-      r.CHANGE_PICTURE = r.PERSONALIZATION.createChild('/changePicture');
-    }
     // </if>
 
     if (pageVisibility.appearance !== false) {
@@ -333,7 +328,11 @@ cr.define('settings', function() {
       // </if>
       // <if expr="chromeos">
       // TODO(crbug.com/950007): Remove when SplitSettings is the default.
-      if (!loadTimeData.getBoolean('isOSSettings')) {
+      if (loadTimeData.getBoolean('isOSSettings')) {
+        r.PERSONALIZATION =
+            r.BASIC.createSection('/personalization', 'personalization');
+        r.CHANGE_PICTURE = r.PERSONALIZATION.createChild('/changePicture');
+      } else {
         r.CHANGE_PICTURE = r.PEOPLE.createChild('/changePicture');
       }
       r.ACCOUNTS = r.PEOPLE.createChild('/accounts');
@@ -449,7 +448,14 @@ cr.define('settings', function() {
       if (pageVisibility.downloads !== false) {
         r.DOWNLOADS = r.ADVANCED.createSection('/downloads', 'downloads');
         // <if expr="chromeos">
-        r.SMB_SHARES = r.DOWNLOADS.createChild('/smbShares');
+        // TODO(crbug.com/950007): Make unconditional and remove 'else' block
+        //     when SplitSettings is the default.
+        if (loadTimeData.getBoolean('isOSSettings')) {
+          r.FILES = r.ADVANCED.createSection('/files', 'files');
+          r.SMB_SHARES = r.FILES.createChild('/smbShares');
+        } else {
+          r.SMB_SHARES = r.DOWNLOADS.createChild('/smbShares');
+        }
         // </if>
       }