Fix gpu_ipc_service_unittests on mac_chromium_rel_ng by managing GL shared groups the same way in s…

ui/gl/gl_context_stub.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/gl/gl_context_stub.h"
 
 namespace gfx {
 
 GLContextStub::GLContextStub() : GLContextReal(nullptr) {}
+GLContextStub::GLContextStub(GLShareGroup* share_group)
+    : GLContextReal(share_group) {}
 
 bool GLContextStub::Initialize(
     GLSurface* compatible_surface, GpuPreference gpu_preference) {
   return true;
 }
 
 bool GLContextStub::MakeCurrent(GLSurface* surface) {
   SetCurrent(surface);
   SetRealGLApi();
   return true;
@@ skipping 14 matching lines @@
 void GLContextStub::OnSetSwapInterval(int interval) {
 }
 
 std::string GLContextStub::GetGLRenderer() {
   return std::string("CHROMIUM");
 }
 
 GLContextStub::~GLContextStub() {}
 
 }  // namespace gfx