Revert "Remove the enable-d3d11 flag so that d3d11 is enabled by default."

ui/gl/gl_surface_win.cc

 // Copyright (c) 2012 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_surface.h"
 
 #include <dwmapi.h>
 
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 277 matching lines @@
     }
     case kGLImplementationMockGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11))
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11) &&
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableD3D11))
     return EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
 
   return EGL_DEFAULT_DISPLAY;
 }
 
 }  // namespace gfx