Change Public Type to Internal in Workspaces Layer:

 The Type PersistentStorageOptions and WeakAction has been changed from Public to Internal since we dont want to expose these types to the Public. (changeset 1213888)

Src/Workspaces/Core/Workspace/Host/Caching/WeakAction.cs

@@ -5,7 +5,7 @@
 
 namespace Microsoft.CodeAnalysis.Host
 {
-    public class WeakAction<TAnchor, TArg> : IWeakAction<TArg> where TAnchor : class
+    internal class WeakAction<TAnchor, TArg> : IWeakAction<TArg> where TAnchor : class
     {
         private readonly WeakReference<TAnchor> owner;
         private readonly Action<TAnchor, TArg> weakAction;

Src/Workspaces/Core/Workspace/Host/PersistentStorage/PersistentStorageOptions.cs

@@ -4,7 +4,7 @@
 
 namespace Microsoft.CodeAnalysis.Host
 {
-    public static class PersistentStorageOptions
+    internal static class PersistentStorageOptions
     {
         public const string OptionName = "FeatureManager/Persistence";