GLKit workaround #trivial (#54)

* GLKit workaround:
canClearContentsOfLayer now turned off for views with CAEAGLLayer

* Nits fixed

* Missed square bracket

* Copyright added

Source/ASDisplayNode.mm

@@ -1,11 +1,23 @@
 //
 //  ASDisplayNode.mm
-//  AsyncDisplayKit
+//  Texture
 //
 //  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
 //  This source code is licensed under the BSD-style license found in the
 //  LICENSE file in the root directory of this source tree. An additional grant
 //  of patent rights can be found in the PATENTS file in the same directory.
+//  Modifications to this file made after 4/13/2017 are: Copyright (c) 2017-present,
+//  Pinterest, Inc.  Licensed under the Apache License, Version 2.0 (the "License");
+//  you may not use this file except in compliance with the License.
+//  You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+//  Unless required by applicable law or agreed to in writing, software
+//  distributed under the License is distributed on an "AS IS" BASIS,
+//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+//  See the License for the specific language governing permissions and
+//  limitations under the License.
 //
 
 #import <AsyncDisplayKit/ASDisplayNodeInternal.h>
@@ -588,6 +600,11 @@ - (UIView *)_locked_viewToLoad
         || [_viewClass isSubclassOfClass:[UIVisualEffectView class]]) {
       self.opaque = NO;
     }
+
+    // CAEAGLLayer
+    if([[view.layer class] isSubclassOfClass:[CAEAGLLayer class]]){
+      _flags.canClearContentsOfLayer = NO;
+    }
   }
 
   return view;