add drawPicture variant that takes a matrix and paint

src/core/SkCanvasPriv.h

Index: src/core/SkCanvasPriv.h
diff --git a/src/core/SkCanvasPriv.h b/src/core/SkCanvasPriv.h
new file mode 100644
index 0000000000000000000000000000000000000000..9f66baa84e4ff99d77acf030d77c8cec3a8ebf24
--- /dev/null
+++ b/src/core/SkCanvasPriv.h
@@ -0,0 +1,23 @@
+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkCanvasPriv_DEFINED
+#define SkCanvasPriv_DEFINED
+
+#include "SkCanvas.h"
+
+class SkAutoCanvasMatrixPaint : SkNoncopyable {
+public:
+    SkAutoCanvasMatrixPaint(SkCanvas*, const SkMatrix*, const SkPaint*, int width, int height);
+    ~SkAutoCanvasMatrixPaint();
+
+private:
+    SkCanvas*   fCanvas;
+    int         fSaveCount;
+};
+
+#endif