Remove alpha/depth/stencil/antialias from WGC3D::Attributes.

third_party/WebKit/public/platform/WebGraphicsContext3D.h

Index: third_party/WebKit/public/platform/WebGraphicsContext3D.h
diff --git a/third_party/WebKit/public/platform/WebGraphicsContext3D.h b/third_party/WebKit/public/platform/WebGraphicsContext3D.h
index 35871ec4bf7173a9184504b1824117c34f71d327..b81e265fc0809d99d621e41b126277564fa25d55 100644
--- a/third_party/WebKit/public/platform/WebGraphicsContext3D.h
+++ b/third_party/WebKit/public/platform/WebGraphicsContext3D.h
@@ -53,10 +53,6 @@ class WebGraphicsContext3D : public WebNonCopyable {
 public:
     // Context creation attributes.
     struct Attributes {
-        bool alpha = true;
-        bool depth = true;
-        bool stencil = true;
-        bool antialias = true;
         bool shareResources = true;
         bool preferDiscreteGPU = false;
         bool noAutomaticFlushes = false;