Clean up EGL thread state at thread exit in nanobench and DM

src/gpu/gl/mac/SkCreatePlatformGLContext_mac.cpp

 
 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 #include "SkTypes.h"
 #if defined(SK_BUILD_FOR_MAC)
 
@@ skipping 108 matching lines @@
         return nullptr;
     }
     MacGLContext* ctx = new MacGLContext;
     if (!ctx->isValid()) {
         delete ctx;
         return nullptr;
     }
     return ctx;
 }
 
+void SkReleasePlatformGLAPIsInThread() {
+}
+
 #endif//defined(SK_BUILD_FOR_MAC)