Add an enable D3D11 flag and blacklist specific intel drivers and windows vista from using D3D11.

ui/gl/gl_surface_egl.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.
 
 // This include must be here so that the includes provided transitively
 // by gl_surface_egl.h don't make it impossible to compile this code.
 #include "third_party/mesa/src/include/GL/osmesa.h"
 
 #include "ui/gl/gl_surface_egl.h"
 
@@ skipping 86 matching lines @@
 
 bool GLSurfaceEGL::InitializeOneOff() {
   static bool initialized = false;
   if (initialized)
     return true;
 
 #if defined(USE_X11)
   g_native_display = base::MessagePumpForUI::GetDefaultXDisplay();
 #elif defined(OS_WIN)
   g_native_display = EGL_DEFAULT_DISPLAY;
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11)) {
+  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11) &&
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableD3D11)) {
     g_native_display = EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
   }
 #elif defined(USE_OZONE)
   ui::SurfaceFactoryOzone* surface_factory =
       ui::SurfaceFactoryOzone::GetInstance();
   if (surface_factory->InitializeHardware() !=
       ui::SurfaceFactoryOzone::INITIALIZED) {
     LOG(ERROR) << "OZONE failed to initialize hardware";
     return false;
   }
@@ skipping 562 matching lines @@
     }
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 #endif
 
 }  // namespace gfx