Add a FOUC painting test.

Source/web/tests/sim/SimCanvas.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef SimCanvas_h
+#define SimCanvas_h
+
+#include "platform/graphics/Color.h"
+#include "third_party/skia/include/core/SkCanvas.h"
+#include "wtf/Vector.h"
+
+namespace blink {
+
+class SimCanvas : public SkCanvas {
+public:
+    SimCanvas(int width, int height);
+
+    enum CommandType {
+        Rect,
+        Text,
+        Image,
+        Shape,
+    };
+
+    // TODO(esprehn): Ideally we'd put the text in here too, but SkTextBlob
+    // has no way to get the text back out so we can't assert about drawn text.
+    struct Command {
+        CommandType type;
+        RGBA32 color;
+    };
+
+    const Vector<Command>& commands() const { return m_commands; }
+
+    // Rect
+    void onDrawRect(const SkRect&, const SkPaint&) override;
+
+    // Shape
+    void onDrawOval(const SkRect&, const SkPaint&) override;
+    void onDrawRRect(const SkRRect&, const SkPaint&) override;
+    void onDrawPath(const SkPath&, const SkPaint&) override;
+
+    // Image
+    void onDrawImage(const SkImage*, SkScalar, SkScalar, const SkPaint*) override;
+    void onDrawImageRect(const SkImage*, const SkRect* src, const SkRect& dst, const SkPaint*, SrcRectConstraint) override;
+
+    // Text
+    void onDrawText(const void* text, size_t byteLength, SkScalar x, SkScalar y, const SkPaint&) override;
+    void onDrawPosText(const void* text, size_t byteLength, const SkPoint pos[], const SkPaint&) override;
+    void onDrawPosTextH(const void* text, size_t byteLength, const SkScalar xpos[], SkScalar constY, const SkPaint&) override;
+    void onDrawTextOnPath(const void* text, size_t byteLength, const SkPath&, const SkMatrix*, const SkPaint&) override;
+    void onDrawTextBlob(const SkTextBlob*, SkScalar x, SkScalar y, const SkPaint&) override;
+
+private:
+    void addCommand(CommandType, RGBA32 = 0);
+
+    Vector<Command> m_commands;
+};
+
+} // namespace blink
+
+#endif