Support ozone=1 compositor_unittests with OSMesa

ui/gl/gl_context_ozone.cc

 // Copyright (c) 2013 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.h"
 
 #include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/sys_info.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_context_egl.h"
+#include "ui/gl/gl_context_osmesa.h"
 #include "ui/gl/gl_context_stub.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface.h"
 
 namespace gfx {
 
 // static
 scoped_refptr<GLContext> GLContext::CreateGLContext(
     GLShareGroup* share_group,
     GLSurface* compatible_surface,
     GpuPreference gpu_preference) {

[jonathan.backer, 2013/06/27 17:13:28]

Could you use a switch here? That way we'll validate that GetGLImplementation is
returning something sane.

[rjkroege, 2013/06/28 00:25:01]

I assume that you mean structure it with the case statement scheme. Done.

   if (GetGLImplementation() == kGLImplementationMockGL)
     return scoped_refptr<GLContext>(new GLContextStub());
 
+  if (GetGLImplementation() == kGLImplementationOSMesaGL) {
+    scoped_refptr<GLContext> context(new GLContextOSMesa(share_group));
+    if (!context->Initialize(compatible_surface, gpu_preference))
+      return NULL;
+    return context;
+  }
+
   scoped_refptr<GLContext> context;
   if (!compatible_surface->GetHandle()) {
     DLOG(ERROR) << "Surface has no associated handle.\n";
     return NULL;
   }

[jonathan.backer, 2013/06/27 17:13:28]

I'm curious why we have this check here. It seems like something that should be
performed in the context initialization (if at all).

[rjkroege, 2013/06/28 00:25:01]

It was unnecessary code. I've removed.

 
   context = new GLContextEGL(share_group);
 
   if (!context->Initialize(compatible_surface, gpu_preference))
     return NULL;
   return context;
 }
 
 }  // namespace gfx