Delete EditorBrowsableAttribute implementation from corefx

Fixes https://github.com/dotnet/corefx/issues/14725


Commit migrated from https://github.com/dotnet/corefx/commit/b58690e859dfdf46cb6327d4a9e29fa3cb160390

src/libraries/System.Runtime/src/ApiCompatBaseline.netcoreapp1.2corert.txt

@@ -255,6 +255,8 @@ MembersMustExist : Member 'System.WeakReference.GetObjectData(System.Runtime.Ser
 CannotRemoveBaseTypeOrInterface : Type 'System.WeakReference<T>' does not implement interface 'System.Runtime.Serialization.ISerializable' in the implementation but it does in the contract.
 MembersMustExist : Member 'System.WeakReference<T>.GetObjectData(System.Runtime.Serialization.SerializationInfo, System.Runtime.Serialization.StreamingContext)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.ComponentModel.DefaultValueAttribute.SetValue(System.Object)' does not exist in the implementation but it does exist in the contract.
+TypesMustExist : Type 'System.ComponentModel.EditorBrowsableAttribute' does not exist in the implementation but it does exist in the contract.
+TypesMustExist : Type 'System.ComponentModel.EditorBrowsableState' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute..ctor(System.Boolean, System.Boolean)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute.DebuggingFlags.get()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute.IsJITOptimizerDisabled.get()' does not exist in the implementation but it does exist in the contract.
@@ -382,4 +384,4 @@ CannotRemoveBaseTypeOrInterface : Type 'System.Threading.Tasks.Task' does not im
 MembersMustExist : Member 'System.Threading.Tasks.Task.Dispose()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Threading.Tasks.Task.Dispose(System.Boolean)' does not exist in the implementation but it does exist in the contract.
 CannotRemoveBaseTypeOrInterface : Type 'System.Threading.Tasks.Task<TResult>' does not implement interface 'System.IDisposable' in the implementation but it does in the contract.
-Total Issues: 383
+Total Issues: 385

src/libraries/System.Runtime/src/ApiCompatBaseline.uap101aot.txt

@@ -255,6 +255,7 @@ MembersMustExist : Member 'System.WeakReference.GetObjectData(System.Runtime.Ser
 CannotRemoveBaseTypeOrInterface : Type 'System.WeakReference<T>' does not implement interface 'System.Runtime.Serialization.ISerializable' in the implementation but it does in the contract.
 MembersMustExist : Member 'System.WeakReference<T>.GetObjectData(System.Runtime.Serialization.SerializationInfo, System.Runtime.Serialization.StreamingContext)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.ComponentModel.DefaultValueAttribute.SetValue(System.Object)' does not exist in the implementation but it does exist in the contract.
+MembersMustExist : Member 'System.ComponentModel.EditorBrowsableAttribute..ctor()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute..ctor(System.Boolean, System.Boolean)' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute.DebuggingFlags.get()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Diagnostics.DebuggableAttribute.IsJITOptimizerDisabled.get()' does not exist in the implementation but it does exist in the contract.
@@ -382,4 +383,4 @@ CannotRemoveBaseTypeOrInterface : Type 'System.Threading.Tasks.Task' does not im
 MembersMustExist : Member 'System.Threading.Tasks.Task.Dispose()' does not exist in the implementation but it does exist in the contract.
 MembersMustExist : Member 'System.Threading.Tasks.Task.Dispose(System.Boolean)' does not exist in the implementation but it does exist in the contract.
 CannotRemoveBaseTypeOrInterface : Type 'System.Threading.Tasks.Task<TResult>' does not implement interface 'System.IDisposable' in the implementation but it does in the contract.
-Total Issues: 383
+Total Issues: 384

src/libraries/System.Runtime/src/System.Runtime.csproj

@@ -33,7 +33,6 @@
     <Compile Include="System\Function.cs" />
     <Compile Include="System\LazyOfTTMetadata.cs" />
     <Compile Include="System\Collections\Generic\ISet.cs" />
-    <Compile Include="System\ComponentModel\EditorBrowsableAttribute.cs" />
     <Compile Include="System\Runtime\CompilerServices\StrongBox.cs" />
     <Compile Include="System\Reflection\RuntimeReflectionExtensions.cs" />
     <Compile Include="System\Runtime\CompilerServices\Attributes.cs" />

src/libraries/System.Runtime/src/System/ComponentModel/EditorBrowsableAttribute.cs

-// Licensed to the .NET Foundation under one or more agreements.
-// The .NET Foundation licenses this file to you under the MIT license.
-// See the LICENSE file in the project root for more information.
-
-namespace System.ComponentModel
-{
-    [AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum | AttributeTargets.Constructor | AttributeTargets.Method | AttributeTargets.Property | AttributeTargets.Field | AttributeTargets.Event | AttributeTargets.Delegate | AttributeTargets.Interface)]
-    public sealed class EditorBrowsableAttribute : Attribute
-    {
-        private EditorBrowsableState browsableState;
-
-        public EditorBrowsableAttribute(EditorBrowsableState state)
-        {
-            browsableState = state;
-        }
-
-        public EditorBrowsableAttribute () : this(EditorBrowsableState.Always) { }
-
-        public EditorBrowsableState State
-        {
-            get { return browsableState; }
-        }
-
-        public override bool Equals(object obj)
-        {
-            if (obj == this)
-            {
-                return true;
-            }
-
-            EditorBrowsableAttribute other = obj as EditorBrowsableAttribute;
-
-            return (other != null) && other.browsableState == browsableState;
-        }
-
-        public override int GetHashCode()
-        {
-            return base.GetHashCode();
-        }
-    }
-
-    public enum EditorBrowsableState
-    {
-        Always,
-        Never,
-        Advanced
-    }
-}