Convert Ozone GL OSMesa implementation.

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_bindings.h"
 #include "ui/gl/gl_gl_api_implementation.h"
-#include "ui/gl/gl_implementation_osmesa.h"
-#include "ui/gl/gl_osmesa_api_implementation.h"
 #include "ui/gl/gl_surface.h"
 #include "ui/gl/init/ozone_util.h"
 
 namespace gl {
 namespace init {
 
 bool InitializeGLOneOffPlatform() {
   if (HasGLOzone())
     return GetGLOzone()->InitializeGLOneOffPlatform();
 
   switch (GetGLImplementation()) {
-    case kGLImplementationOSMesaGL:
     case kGLImplementationMockGL:
     case kGLImplementationStubGL:
       return true;
     default:
-      return false;
+      NOTREACHED();
   }
+  return false;
 }
 
 bool InitializeStaticGLBindings(GLImplementation implementation) {
   // 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.
   DCHECK_EQ(kGLImplementationNone, GetGLImplementation());
 
   if (HasGLOzone(implementation)) {
     return GetGLOzone(implementation)
         ->InitializeStaticGLBindings(implementation);
   }
 
   switch (implementation) {
-    case kGLImplementationOSMesaGL:
-      return InitializeStaticGLBindingsOSMesaGL();
     case kGLImplementationMockGL:
     case kGLImplementationStubGL:
       SetGLImplementation(implementation);
       InitializeStaticGLBindingsGL();
       return true;
     default:
       NOTREACHED();
   }
 
   return false;
 }
 
 void InitializeDebugGLBindings() {
   if (HasGLOzone()) {
     GetGLOzone()->InitializeDebugGLBindings();
     return;
   }
 
   InitializeDebugGLBindingsGL();
-  InitializeDebugGLBindingsOSMESA();
 }
 
 void ShutdownGLPlatform() {
   if (HasGLOzone()) {
     GetGLOzone()->ShutdownGL();
     return;
   }
 
   ClearBindingsGL();
-  ClearBindingsOSMESA();
 }
 
 }  // namespace init
 }  // namespace gl