Enable surprise me wallpaper for new profiles.

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

Index: chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js
diff --git a/chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js b/chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js
index 71062033f168ba4bc7d028f2f65f0f07528ae82b..52b9e62a416dcc7bf7e2b846f3136306b635fde9 100644
--- a/chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js
+++ b/chrome/browser/resources/chromeos/wallpaper_manager/js/event_page.js
@@ -274,3 +274,16 @@ chrome.storage.onChanged.addListener(function(changes, namespace) {
 chrome.alarms.onAlarm.addListener(function() {
   SurpriseWallpaper.getInstance().next();
 });
+
+/**
+ * Enables surprise me wallpaper iff it has not already been configured.
+ */
+chrome.wallpaperPrivate.onRequestEnableSurpriseMe.addListener(function() {
+  Constants.WallpaperSyncStorage.get(Constants.AccessSurpriseMeEnabledKey,
+                                      function(items) {
+    if (!items.hasOwnProperty(Constants.AccessSurpriseMeEnabledKey)) {

[Nikita (slow), 2014/04/08 16:58:27]

I wonder if that's the right time to check for this property since it may not
have been synced at this point.

[Harry McCleave, 2014/04/09 02:41:33]

My impression was that if this sync fails for whatever reason, a local copy of
the preferences will split off and when sync succeeds conflicts will be resolved
in the favor of the server values which would be the intended behaviour?

[bshe, 2014/04/09 14:32:15]

Is this going to be called when an existing user logged in on a new device? If
so, it might be safer to delay this operation for something like 1 hour or so
(or after sync is done if we can detect such event). Otherwise, we may change
the wallpaper of existing user first and then revert to the correct one. It may
confuse user.

On 2014/04/09 02:41:33, Harry McCleave wrote:

+      WallpaperUtil.saveToStorage(Constants.AccessSurpriseMeEnabledKey,
+                                  true, true);
+    }
+  });
+});