Fix preferred order of GL implementations.

ui/gfx/gl/gl_implementation_linux.cc

 // Copyright (c) 2011 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 <vector>
 
 #include "base/base_paths.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/lazy_instance.h"
@@ skipping 40 matching lines @@
 #if (defined(TOOLKIT_VIEWS) && !defined(OS_CHROMEOS)) || defined(TOUCH_UI)
 base::LazyInstance<base::Lock,
                    base::LeakyLazyInstanceTraits<base::Lock> >
     g_lock = LAZY_INSTANCE_INITIALIZER;
 #endif
 
 }  // namespace anonymous
 
 void GetAllowedGLImplementations(std::vector<GLImplementation>* impls) {
 #if !defined(USE_WAYLAND)
-  impls->push_back(kGLImplementationOSMesaGL);
   impls->push_back(kGLImplementationDesktopGL);
 #endif
   impls->push_back(kGLImplementationEGLGLES2);
+#if !defined(USE_WAYLAND)
+  impls->push_back(kGLImplementationOSMesaGL);
+#endif
 }
 
 bool InitializeGLBindings(GLImplementation implementation) {
 #if (defined(TOOLKIT_VIEWS) && !defined(OS_CHROMEOS)) || defined(TOUCH_UI)
   base::AutoLock locked(g_lock.Get());
 #endif
   // Prevent reinitialization with a different implementation. Once the gpu
   // unit tests have initialized with kGLImplementationMock, we don't want to
   // later switch to another GL implementation.
   if (GetGLImplementation() != kGLImplementationNone)
@@ skipping 156 matching lines @@
 #if !defined(USE_WAYLAND)
   ClearGLBindingsGLX();
   ClearGLBindingsOSMESA();
 #endif
   SetGLImplementation(kGLImplementationNone);
 
   UnloadGLNativeLibraries();
 }
 
 }  // namespace gfx