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

ui/gl/gl_surface_egl.h

 // 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.
 
 #ifndef UI_GL_GL_SURFACE_EGL_H_
 #define UI_GL_GL_SURFACE_EGL_H_
 
 #if defined(OS_WIN)
 #include <windows.h>
 #endif
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/time/time.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/vsync_provider.h"
 #include "ui/gl/gl_bindings.h"
 #include "ui/gl/gl_surface.h"
 
 namespace gfx {
 
 // Get default EGL display for GLSurfaceEGL (differs by platform).
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay();
+#if defined(OS_WIN)
+// Windows must call eglGetPlatformDisplayEXT to get ANGLE to enable WARP, so
+// we define additional data helpers to provide values for the additional
+// required arguments for that method.
+const EGLint* GetPlatformDefaultEGLNativeDisplayAttributes();
+const EGLenum GetPlatformDefaultEGLNativePlatform();
+#endif
 
 // Interface for EGL surface.
 class GL_EXPORT GLSurfaceEGL : public GLSurface {
  public:
   GLSurfaceEGL();
 
   // Implement GLSurface.
   virtual EGLDisplay GetDisplay() OVERRIDE;
 
   static bool InitializeOneOff();
@@ skipping 102 matching lines @@
   virtual ~SurfacelessEGL();
 
  private:
   gfx::Size size_;
   DISALLOW_COPY_AND_ASSIGN(SurfacelessEGL);
 };
 
 }  // namespace gfx
 
 #endif  // UI_GL_GL_SURFACE_EGL_H_