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

ui/gl/gl_surface_win.cc

Index: ui/gl/gl_surface_win.cc
diff --git a/ui/gl/gl_surface_win.cc b/ui/gl/gl_surface_win.cc
index 000110368d94a0cbe547213979675b1fcffef10c..e16464315d608130e7df5a3907fba9d9158f423d 100644
--- a/ui/gl/gl_surface_win.cc
+++ b/ui/gl/gl_surface_win.cc
@@ -25,6 +25,15 @@
 #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 {
 
@@ -294,10 +303,23 @@ scoped_refptr<GLSurface> GLSurface::CreateOffscreenGLSurface(
 }
 
 EGLNativeDisplayType GetPlatformDefaultEGLNativeDisplay() {
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(switches::kDisableD3D11))
-    return EGL_D3D11_ELSE_D3D9_DISPLAY_ANGLE;
+  return GetDC(NULL);
+}
+
+static const EGLint kDisplayAttribsWarp[] {
+  EGL_PLATFORM_ANGLE_TYPE_ANGLE,
+  EGL_PLATFORM_ANGLE_TYPE_D3D11_WARP_ANGLE,
+  EGL_NONE
+};
+
+const EGLenum GetPlatformDefaultEGLNativePlatform() {
+  return EGL_PLATFORM_ANGLE_ANGLE;
+}
 
-  return EGL_DEFAULT_DISPLAY;
+const EGLint* GetPlatformDefaultEGLNativeDisplayAttributes() {
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUseWarp))
+    return kDisplayAttribsWarp;
+  return NULL;
 }
 
 }  // namespace gfx