Move GL one-off initialization code.

ui/gl/init/gl_initializer_ozone.cc

+// Copyright 2016 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/init/gl_initializer.h"
+
+#include "base/logging.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/gl_surface_egl.h"
+
+namespace gl {
+namespace init {
+
+bool InitializeGLOneOffPlatform() {
+  switch (GetGLImplementation()) {
+    case kGLImplementationEGLGLES2:
+      if (!GLSurfaceEGL::InitializeOneOff()) {
+        LOG(ERROR) << "GLSurfaceEGL::InitializeOneOff failed.";
+        return false;
+      }
+      return true;
+    case kGLImplementationOSMesaGL:
+    case kGLImplementationMockGL:
+      return true;
+    default:
+      return false;
+  }
+}
+
+}  // namespace init
+}  // namespace gl