adds WARP support to Chromium, for Metro mode only, on Windows 8

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"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/win/windows_version.h"
 #include "ui/gfx/frame_time.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_implementation.h"
 #include "ui/gl/gl_surface_egl.h"
 #include "ui/gl/gl_surface_osmesa.h"
 #include "ui/gl/gl_surface_stub.h"
 #include "ui/gl/gl_surface_wgl.h"
 
 // From ANGLE's egl/eglext.h.
 #if !defined(EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE)
 #define EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE \
   reinterpret_cast<EGLNativeDisplayType>(-2)
 #endif
+#if !defined(EGL_PLATFORM_ANGLE_ANGLE)
+#define EGL_PLATFORM_ANGLE_ANGLE 0x3201
+#endif
+#if !defined(EGL_PLATFORM_ANGLE_TYPE_ANGLE)
+#define EGL_PLATFORM_ANGLE_TYPE_ANGLE 0x3202
+#endif
+#if !defined(EGL_PLATFORM_ANGLE_TYPE_D3D11_WARP_ANGLE)
+#define EGL_PLATFORM_ANGLE_TYPE_D3D11_WARP_ANGLE 0x3206
+#endif
 
 namespace gfx {
 
 // This OSMesa GL surface can use GDI to swap the contents of the buffer to a
 // view.
 class NativeViewGLSurfaceOSMesa : public GLSurfaceOSMesa {
  public:
   explicit NativeViewGLSurfaceOSMesa(gfx::AcceleratedWidget window);
   virtual ~NativeViewGLSurfaceOSMesa();
 
@@ skipping 249 matching lines @@
     }
     case kGLImplementationMockGL:
       return new GLSurfaceStub;
     default:
       NOTREACHED();
       return NULL;
   }
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11))
-    return EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
-
-  return EGL_DEFAULT_DISPLAY;
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11) ||
+      CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseWarp))
+    return GetDC(NULL);
+  return EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
 }
 
 }  // namespace gfx