Move from OsuGameBase to OsuGame

Also moves to a more suitable namespace.

osu.Game/Beatmaps/DifficultyRecommender.cs

@@ -9,13 +9,16 @@ using osu.Framework.Allocation;
 using osu.Framework.Bindables;
 using osu.Framework.Extensions.IEnumerableExtensions;
 using osu.Framework.Graphics;
-using osu.Game.Beatmaps;
 using osu.Game.Online.API;
 using osu.Game.Online.API.Requests;
 using osu.Game.Rulesets;
 
-namespace osu.Game.Screens.Select
+namespace osu.Game.Beatmaps
 {
+    /// <summary>
+    /// A class which will recommend the most suitable difficulty for the local user from a beatmap set.
+    /// This requires the user to be logged in, as it sources from the user's online profile.
+    /// </summary>
     public class DifficultyRecommender : Component
     {
         [Resolved]

osu.Game/OsuGame.cs

@@ -80,6 +80,9 @@ namespace osu.Game
 
         private BeatmapSetOverlay beatmapSetOverlay;
 
+        [Cached]
+        private readonly DifficultyRecommender difficultyRecommender = new DifficultyRecommender();
+
         [Cached]
         private readonly ScreenshotManager screenshotManager = new ScreenshotManager();
 
@@ -374,7 +377,7 @@ namespace osu.Game
                     beatmaps = databasedSet.Beatmaps;
 
                 // Prefer recommended beatmap if recommendations are available, else fallback to a sane selection.
-                var selection = DifficultyRecommender.GetRecommendedBeatmap(beatmaps)
+                var selection = difficultyRecommender.GetRecommendedBeatmap(beatmaps)
                                 ?? beatmaps.FirstOrDefault(b => b.Ruleset.Equals(Ruleset.Value))
                                 ?? beatmaps.First();
 
@@ -639,6 +642,8 @@ namespace osu.Game
                 GetStableStorage = GetStorageForStableInstall
             }, Add, true);
 
+            loadComponentSingleFile(difficultyRecommender, Add);
+
             loadComponentSingleFile(screenshotManager, Add);
 
             // dependency on notification overlay, dependent by settings overlay

osu.Game/OsuGameBase.cs

@@ -36,7 +36,6 @@ using osu.Game.Resources;
 using osu.Game.Rulesets;
 using osu.Game.Rulesets.Mods;
 using osu.Game.Scoring;
-using osu.Game.Screens.Select;
 using osu.Game.Skinning;
 using osuTK.Input;
 using RuntimeInfo = osu.Framework.RuntimeInfo;
@@ -99,9 +98,6 @@ namespace osu.Game
         [Cached(typeof(IBindable<IReadOnlyList<Mod>>))]
         protected readonly Bindable<IReadOnlyList<Mod>> SelectedMods = new Bindable<IReadOnlyList<Mod>>(Array.Empty<Mod>());
 
-        [Cached]
-        protected readonly DifficultyRecommender DifficultyRecommender = new DifficultyRecommender();
-
         /// <summary>
         /// Mods available for the current <see cref="Ruleset"/>.
         /// </summary>
@@ -306,8 +302,6 @@ namespace osu.Game
             AddInternal(MusicController = new MusicController());
             dependencies.CacheAs(MusicController);
 
-            Add(DifficultyRecommender);
-
             Ruleset.BindValueChanged(onRulesetChanged);
         }