Move GL one-off initialization code.

ui/gl/init/gl_initializer.h

+// 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.
+
+#ifndef UI_GL_INIT_GL_INITIALIZER_H_
+#define UI_GL_INIT_GL_INITIALIZER_H_
+
+#include "base/macros.h"
+#include "ui/gl/gl_implementation.h"
+#include "ui/gl/init/gl_init_export.h"
+
+namespace gl {
+namespace init {
+
+// Class to encapsulate code for GL initialization. To perform GL initialization
+// you want to call gl::init::InitializeGLOneOff() or for tests possibly
+// gl::init::GLInitializer::InitializeOneOffImplementation(...).
+class GL_INIT_EXPORT GLInitializer {

[piman, 2016/06/03 00:47:05]

nit: is a class needed at all? If it only has static functions a namespace is
preferred (per style), but then again gl::init is already that.

If the matter is to leave InitializeOneOffPlatform private, maybe we can just
move it to a ui/gl/init/gl_initializer_internal.h or something

[kylechar, 2016/06/03 13:41:21]

Yep, it was just to hide InitializeOneOffPlatform but, that's probably a bit too
Java-y. I've removed the class and moved the code for InitializeGLOneOff() and
InitializeGLOneOffImplementation() to gl_factory instead. I've also made it such
that gl_initializer.h is a private header, so code outside the //ui/gl/init
target can't include it.

+ public:
+  GLInitializer() = delete;
+
+  // Performs generic one-off GL initialization, calling into the appropriate
+  // platform dependent initialization code.
+  static bool InitializeOneOffImplementation(GLImplementation impl,
+                                             bool fallback_to_osmesa,
+                                             bool gpu_service_logging,
+                                             bool disable_gl_drawing);
+
+ private:
+  // Performs platform dependent one-off GL initialization, calling into the
+  // appropriate GLSurface code to initialize it. This is only called from
+  // InitializeOneOffImplementation().
+  static bool InitializeOneOffPlatform();
+};
+
+}  // namespace init
+}  // namespace gl
+
+#endif  // UI_GL_INIT_GL_INITIALIZER_H_