Revert binary backward-incompatible changes

 * bf19ad6: Make `Mock.Object` non-virtual
 * ccf9a02: Remove yet another superfluous extension method class
 * 49a2ccf: Rename extension method for `mock.Protected()`
 * 41ef023: Put async extension methods in `AsyncExtensions`
 * 8aacd8b: Remove superfluous extension methods
 * f605bfe: Fix name of class gen'd by `ReturnsExtensions.tt`
 * 6fadc8f: Merge `ObsoleteMockExtensions` into `MockExtensions`
 * 0cbdd87: Convert `Expect*` methods into extension methods
 * 0669d43: Remove redundant class `MockLegacyExtensions`
 * 85e0e7d: `MockFactory` <--> `MockRepository`

Those would be completely fine for people relying on Moq directly, as
they could simply recompile their code. However, for anyone using Moq
through a 3rd-party library that was compiled against an earlier ver-
sion, they break user code due to binary incompatibility. Forcing all
3rd-party libs to recompile and republish without protecting them with
a semver major version increase is perhaps asking a bit much. :)

Author: stakx

src/Moq/AsInterface.cs

@@ -50,6 +50,11 @@ public override DefaultValueProvider DefaultValueProvider
 
 		internal override Type[] InheritedInterfaces => this.owner.InheritedInterfaces;
 
+		public override TInterface Object
+		{
+			get { return this.owner.Object as TInterface; }
+		}
+
 		internal override SetupCollection Setups => this.owner.Setups;
 
 		public override Switches Switches
@@ -65,7 +70,10 @@ public override Mock<TNewInterface> As<TNewInterface>()
 			return this.owner.As<TNewInterface>();
 		}
 
-		protected internal override object OnGetObject() => this.owner.OnGetObject();
+		protected override object OnGetObject()
+		{
+			return this.owner.Object;
+		}
 
 		public override string ToString()
 		{

src/Moq/DefaultValue.cs

@@ -34,9 +34,9 @@ public enum DefaultValue
 		///     are represented by this enumeration value.
 		///   </para>
 		///   <para>
-		///     Do not set <see cref="Mock.DefaultValue"/> (nor <see cref="MockRepository.DefaultValue"/>) to this value.
+		///     Do not set <see cref="Mock.DefaultValue"/> (nor <see cref="MockFactory.DefaultValue"/>) to this value.
 		///     If you want to set up a custom default value generation strategy, set <see cref="Mock.DefaultValueProvider"/>
-		///     or <see cref="MockRepository.DefaultValueProvider"/> instead.
+		///     or <see cref="MockFactory.DefaultValueProvider"/> instead.
 		///   </para>
 		/// </summary>
 		/// <remarks>

src/Moq/Mock.Generic.cs

@@ -183,7 +183,10 @@ public override DefaultValueProvider DefaultValueProvider
 		/// <include file='Mock.Generic.xdoc' path='docs/doc[@for="Mock{T}.Object"]/*'/>
 		[SuppressMessage("Microsoft.Naming", "CA1716:IdentifiersShouldNotMatchKeywords", MessageId = "Object", Justification = "Exposes the mocked object instance, so it's appropriate.")]
 		[SuppressMessage("Microsoft.Naming", "CA1721:PropertyNamesShouldNotMatchGetMethods", Justification = "The public Object property is the only one visible to Moq consumers. The protected member is for internal use only.")]
-		public new T Object => (T)this.OnGetObject();
+		public virtual new T Object
+		{
+			get { return (T)base.Object; }
+		}
 
 		/// <include file='Mock.Generic.xdoc' path='docs/doc[@for="Mock{T}.Name"]/*'/>
 		public string Name
@@ -198,25 +201,30 @@ public override string ToString()
 			return this.Name;
 		}
 
+		private void InitializeInstance()
+		{
+			// Determine the set of interfaces that the proxy object should additionally implement.
+			var additionalInterfaceCount = this.AdditionalInterfaces.Count;
+			var interfaces = new Type[1 + additionalInterfaceCount];
+			interfaces[0] = typeof(IMocked<T>);
+			this.AdditionalInterfaces.CopyTo(0, interfaces, 1, additionalInterfaceCount);
+
+			this.instance = (T)ProxyFactory.Instance.CreateProxy(
+				typeof(T),
+				this,
+				interfaces,
+				this.constructorArguments);
+		}
+
 		/// <summary>
 		/// Returns the mocked object value.
 		/// </summary>
 		[SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate", Justification = "This is actually the protected virtual implementation of the property Object.")]
-		protected internal override object OnGetObject()
+		protected override object OnGetObject()
 		{
 			if (this.instance == null)
 			{
-				// Determine the set of interfaces that the proxy object should additionally implement.
-				var additionalInterfaceCount = this.AdditionalInterfaces.Count;
-				var interfaces = new Type[1 + additionalInterfaceCount];
-				interfaces[0] = typeof(IMocked<T>);
-				this.AdditionalInterfaces.CopyTo(0, interfaces, 1, additionalInterfaceCount);
-
-				this.instance = (T)ProxyFactory.Instance.CreateProxy(
-					typeof(T),
-					this,
-					interfaces,
-					this.constructorArguments);
+				this.InitializeInstance();
 			}
 
 			return this.instance;

src/Moq/Mock.cs

@@ -163,7 +163,7 @@ public DefaultValue DefaultValue
 
 		/// <include file='Mock.xdoc' path='docs/doc[@for="Mock.OnGetObject"]/*'/>
 		[SuppressMessage("Microsoft.Design", "CA1024:UsePropertiesWhereAppropriate", Justification = "This is actually the protected virtual implementation of the property Object.")]
-		protected internal abstract object OnGetObject();
+		protected abstract object OnGetObject();
 
 		/// <summary>
 		/// Retrieves the type of the mocked object, its generic type argument.

src/Moq/MockException.cs

@@ -189,7 +189,7 @@ internal static MockException FromInnerMockOf(Setup setup, MockException error)
 		/// <summary>
 		///   Returns an exception whose message is the concatenation of the given <paramref name="errors"/>' messages
 		///   and whose reason(s) is the combination of the given <paramref name="errors"/>' reason(s).
-		///   Used by <see cref="MockRepository.VerifyMocks(Action{Mock})"/> when it finds one or more mocks with verification errors.
+		///   Used by <see cref="MockFactory.VerifyMocks(Action{Mock})"/> when it finds one or more mocks with verification errors.
 		/// </summary>
 		internal static MockException Combined(IEnumerable<MockException> errors, string preamble)
 		{

src/Moq/MockExtensions.cs

@@ -3,8 +3,6 @@
 
 using System.ComponentModel;
 
-using Moq.Language;
-
 namespace Moq
 {
 	/// <summary>
@@ -13,17 +11,6 @@ namespace Moq
 	[EditorBrowsable(EditorBrowsableState.Never)]
 	public static partial class MockExtensions
 	{
-		/// <summary>
-		///   Perform an expectation in the trace.
-		/// </summary>
-		public static ISetupConditionResult<T> InSequence<T>(this Mock<T> mock, MockSequence sequence)
-			where T : class
-		{
-			Guard.NotNull(sequence, nameof(sequence));
-
-			return sequence.For(mock);
-		}
-
 		/// <summary>
 		/// Resets this mock's state. This includes its setups, configured default return values, registered event handlers, and all recorded invocations.
 		/// </summary>