diff -r 000000000000 -r 6474c204b198 content/canvas/src/WebGLContextUtils.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/canvas/src/WebGLContextUtils.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef WEBGLCONTEXTUTILS_H_
+#define WEBGLCONTEXTUTILS_H_
+
+#include "WebGLContext.h"
+#include "mozilla/Assertions.h"
+#include "mozilla/dom/BindingUtils.h"
+
+namespace mozilla {
+
+bool IsGLDepthFormat(GLenum webGLFormat);
+bool IsGLDepthStencilFormat(GLenum webGLFormat);
+bool FormatHasAlpha(GLenum webGLFormat);
+void DriverFormatsFromFormatAndType(gl::GLContext* gl, GLenum webGLFormat, GLenum webGLType,
+                                    GLenum* out_driverInternalFormat, GLenum* out_driverFormat);
+GLenum DriverTypeFromType(gl::GLContext* gl, GLenum webGLType);
+
+template <typename WebGLObjectType>
+JS::Value
+WebGLContext::WebGLObjectAsJSValue(JSContext *cx, const WebGLObjectType *object, ErrorResult& rv) const
+{
+    if (!object) {
+        return JS::NullValue();
+    }
+    MOZ_ASSERT(this == object->Context());
+    JS::Rooted<JS::Value> v(cx);
+    JS::Rooted<JSObject*> wrapper(cx, GetWrapper());
+    JSAutoCompartment ac(cx, wrapper);
+    if (!dom::WrapNewBindingObject(cx, const_cast<WebGLObjectType*>(object), &v)) {
+        rv.Throw(NS_ERROR_FAILURE);
+        return JS::NullValue();
+    }
+    return v;
+}
+
+template <typename WebGLObjectType>
+JSObject*
+WebGLContext::WebGLObjectAsJSObject(JSContext *cx, const WebGLObjectType *object, ErrorResult& rv) const
+{
+    JS::Value v = WebGLObjectAsJSValue(cx, object, rv);
+    if (v.isNull()) {
+        return nullptr;
+    }
+    return &v.toObject();
+}
+
+} // namespace mozilla
+
+#endif // WEBGLCONTEXTUTILS_H_