Adds basic sprite sheet support to sprites

sky/engine/core/painting/Canvas.cpp

 // 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.
 
 #include "math.h"
 
 #include "sky/engine/config.h"
 #include "sky/engine/core/painting/Canvas.h"
 
 #include "sky/engine/core/dom/Document.h"
@@ skipping 200 matching lines @@
                        float x,
                        float y,
                        const Paint* paint) {
   if (!m_canvas)
     return;
   ASSERT(image);
   ASSERT(m_displayList->isRecording());
   m_canvas->drawBitmap(image->bitmap(), x, y, &paint->paint());
 }
 
+void Canvas::drawImageRect(const CanvasImage* image, Rect& src, Rect& dst, Paint* paint) {

[eseidel, 2015/06/23 23:22:31]

I'm not sure this name is immediately clear to me.  Should we just match the
Skia name?

drawBitmapRectToRect?

drawImageRectToRect?

+  if (!m_canvas)
+    return;
+  ASSERT(image);
+  ASSERT(m_displayList->isRecording());
+  m_canvas->drawBitmapRectToRect(image->bitmap(), &src.sk_rect, dst.sk_rect, &paint->paint());

[eseidel, 2015/06/23 23:22:31]

I think this file uses 4 space indent.

+}
+
 PassRefPtr<DisplayList> Canvas::finishRecording()
 {
     if (!isRecording())
         return nullptr;
     m_canvas = nullptr;
     m_displayList->endRecording();
     return m_displayList.release();
 }
 
 } // namespace blink