Flesh out the Painting API a bit.

sky/engine/core/painting/PaintingContext.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 SKY_ENGINE_CORE_PAINTING_PAINTINGCONTEXT_H_
 #define SKY_ENGINE_CORE_PAINTING_PAINTINGCONTEXT_H_
 
 #include "sky/engine/core/painting/Paint.h"
 #include "sky/engine/platform/graphics/DisplayList.h"
 #include "sky/engine/tonic/dart_wrappable.h"
 #include "sky/engine/wtf/PassRefPtr.h"
 #include "sky/engine/wtf/RefCounted.h"
+#include "sky/engine/wtf/Vector.h"
 
 namespace blink {
 class Element;
 
 class PaintingContext : public RefCounted<PaintingContext>, public DartWrappable {
     DEFINE_WRAPPERTYPEINFO();
 public:
     ~PaintingContext() override;
     static PassRefPtr<PaintingContext> create(PassRefPtr<Element> element, const FloatSize& size);
 
     double height() const { return m_size.height(); }
     double width() const { return m_size.width(); }
 
+    void save();
+    void saveLayer(Vector<float> bounds, Paint* paint);
+    void restore();
+
+    void translate(float dx, float dy);
+    void scale(float sx, float sy);
+    void rotate(float degrees);
+    void skew(float sx, float sy);
+    void concat(Vector<float> matrix);
+
+    void clipRect(Vector<float> rect);
+
+    void drawPaint(Paint* paint);
+    void drawRect(Vector<float> rect, Paint* paint);
+    void drawOval(Vector<float> rect, Paint* paint);
     void drawCircle(double x, double y, double radius, Paint* paint);
+
     void commit();
 
 private:
     PaintingContext(PassRefPtr<Element> element, const FloatSize& size);
 
     RefPtr<Element> m_element;
     FloatSize m_size;
     RefPtr<DisplayList> m_displayList;
     SkCanvas* m_canvas;
 };
 
 } // namespace blink
 
 #endif  // SKY_ENGINE_CORE_PAINTING_PAINTINGCONTEXT_H_