LibWeb: Add the ability to retrieve a WebGL context from getContext

Userland/Libraries/LibWeb/WebGL/WebGLContextAttributes.h

@@ -0,0 +1,34 @@
+/*
+ * Copyright (c) 2022, Luke Wilde <lukew@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibJS/Forward.h>
+
+namespace Web::WebGL {
+
+enum class WebGLPowerPreference {
+    Default,
+    LowPower,
+    HighPerformance,
+};
+
+// https://www.khronos.org/registry/webgl/specs/latest/1.0/#WEBGLCONTEXTATTRIBUTES
+struct WebGLContextAttributes {
+    bool alpha { true };
+    bool depth { true };
+    bool stencil { false };
+    bool antialias { true };
+    bool premultiplied_alpha { true };
+    bool preserve_drawing_buffer { false };
+    WebGLPowerPreference power_preference { WebGLPowerPreference::Default };
+    bool fail_if_major_performance_caveat { false };
+    bool desynchronized { false };
+};
+
+JS::ThrowCompletionOr<WebGLContextAttributes> convert_value_to_context_attributes_dictionary(JS::GlobalObject& global_object, JS::Value value);
+
+}