[CrOS Wallpaper] Hide 'center' and 'center cropped' buttons on default.

Do not show "Center" and "Center Cropped" if the wallpaper is
of type 'OemDefaultWallpaper'.  These buttons should only be shown
when the Currently Set image is the user's.

Bug: 973011
Change-Id: Ib1899f430854fa928d807af552b79c51ed3b8ea6
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1854797
Commit-Queue: Regan Hsu <hsuregan@chromium.org>
Reviewed-by: Xiaoqian Dai <xdai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#705310}

chrome/browser/resources/chromeos/wallpaper_manager/js/wallpaper_manager.js

@@ -57,6 +57,9 @@ function WallpaperManager(dialogDom) {
 // TODO(bshe): Get rid of anonymous namespace.
 (function() {
 
+// Default wallpaper url
+var OEM_DEFAULT_WALLPAPER_URL = 'OemDefaultWallpaper';
+
 /**
  * The following values should be kept in sync with the style sheet.
  */
@@ -461,7 +464,8 @@ WallpaperManager.prototype.decorateCurrentWallpaperInfoBar_ = function() {
       currentWallpaperInfo => {
         // Initialize the "more options" buttons.
         var isOnlineWallpaper = !!currentWallpaperInfo;
-        var isDefaultWallpaper = !this.currentWallpaper_;
+        var isDefaultWallpaper = !this.currentWallpaper_ ||
+            this.currentWallpaper_ == OEM_DEFAULT_WALLPAPER_URL;
         var visibleItemList = [];
         $('refresh').hidden = !isOnlineWallpaper || !this.dailyRefreshInfo_ ||
             !this.dailyRefreshInfo_.enabled;
@@ -1288,7 +1292,7 @@ WallpaperManager.prototype.onCategoriesChange_ = function() {
     if (loadTimeData.getBoolean('isOEMDefaultWallpaper')) {
       var defaultWallpaperInfo = {
         wallpaperId: null,
-        baseURL: 'OemDefaultWallpaper',
+        baseURL: OEM_DEFAULT_WALLPAPER_URL,
         layout: Constants.WallpaperThumbnailDefaultLayout,
         source: Constants.WallpaperSourceEnum.OEM,
         ariaLabel: loadTimeData.getString('defaultWallpaperLabel'),
@@ -1704,5 +1708,4 @@ WallpaperManager.prototype.disableDailyRefresh_ = function() {
   this.updateDailyRefreshItemStates_(this.dailyRefreshInfo_);
   this.decorateCurrentWallpaperInfoBar_();
 };
-
 })();