LibWeb: Extract CanvasDrawPath class from CRC2D

Again, this is an entirely virtual class since the methods involve
direct access to the Painter. Though, maybe I could just expose the
Painter...

Userland/Libraries/LibWeb/HTML/Canvas/CanvasDrawPath.h

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2022, Sam Atkins <atkinssj@serenityos.org>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/String.h>
+#include <LibWeb/HTML/Path2D.h>
+
+namespace Web::HTML {
+
+// https://html.spec.whatwg.org/multipage/canvas.html#canvasdrawpath
+class CanvasDrawPath {
+public:
+    virtual ~CanvasDrawPath() = default;
+
+    virtual void begin_path() = 0;
+
+    virtual void fill(String const& fill_rule) = 0;
+    virtual void fill(Path2D& path, String const& fill_rule) = 0;
+
+    virtual void stroke() = 0;
+    virtual void stroke(Path2D const& path) = 0;
+
+    virtual void clip() = 0;
+
+protected:
+    CanvasDrawPath() = default;
+};
+
+}

Userland/Libraries/LibWeb/HTML/Canvas/CanvasDrawPath.idl

@@ -0,0 +1,25 @@
+#import <HTML/Path2D.idl>
+
+// https://html.spec.whatwg.org/multipage/canvas.html#canvasfillrule
+enum CanvasFillRule { "nonzero", "evenodd" };
+
+// https://html.spec.whatwg.org/multipage/canvas.html#canvasdrawpath
+interface mixin CanvasDrawPath {
+    undefined beginPath();
+    // FIXME: `DOMString` should be `CanvasFillRule`
+    undefined fill(optional DOMString fillRule = "nonzero");
+    // FIXME: `DOMString` should be `CanvasFillRule`
+    undefined fill(Path2D path, optional DOMString fillRule = "nonzero");
+    undefined stroke();
+    undefined stroke(Path2D path);
+
+    // FIXME: Replace this with these two definitions:
+    // undefined clip(optional CanvasFillRule fillRule = "nonzero");
+    // undefined clip(Path2D path, optional CanvasFillRule fillRule = "nonzero");
+    undefined clip();
+
+    // FIXME: boolean isPointInPath(unrestricted double x, unrestricted double y, optional CanvasFillRule fillRule = "nonzero");
+    // FIXME: boolean isPointInPath(Path2D path, unrestricted double x, unrestricted double y, optional CanvasFillRule fillRule = "nonzero");
+    // FIXME: boolean isPointInStroke(unrestricted double x, unrestricted double y);
+    // FIXME: boolean isPointInStroke(Path2D path, unrestricted double x, unrestricted double y);
+};