Add scale and skew to C canvas API

src/c/sk_surface.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "sk_canvas.h"
 #include "sk_image.h"
 #include "sk_paint.h"
@@ skipping 290 matching lines @@
 }
 
 void sk_canvas_translate(sk_canvas_t* ccanvas, float dx, float dy) {
     AsCanvas(ccanvas)->translate(dx, dy);
 }
 
 void sk_canvas_scale(sk_canvas_t* ccanvas, float sx, float sy) {
     AsCanvas(ccanvas)->scale(sx, sy);
 }
 
+void sk_canvas_rotate_degress(sk_canvas_t* ccanvas, float degrees) {
+    AsCanvas(ccanvas)->rotate(degrees);
+}
+
+void sk_canvas_rotate_radians(sk_canvas_t* ccanvas, float radians) {
+    AsCanvas(ccanvas)->rotate(SkRadiansToDegrees(radians));
+}
+
+void sk_canvas_skew(sk_canvas_t* ccanvas, float sx, float sy) {
+    AsCanvas(ccanvas)->skew(sx, sy);
+}
+
 void sk_canvas_draw_paint(sk_canvas_t* ccanvas, const sk_paint_t* cpaint) {
     AsCanvas(ccanvas)->drawPaint(AsPaint(*cpaint));
 }
 
 void sk_canvas_draw_rect(sk_canvas_t* ccanvas, const sk_rect_t* crect, const sk_paint_t* cpaint) {
     AsCanvas(ccanvas)->drawRect(AsRect(*crect), AsPaint(*cpaint));
 }
 
 void sk_canvas_draw_oval(sk_canvas_t* ccanvas, const sk_rect_t* crect, const sk_paint_t* cpaint) {
     AsCanvas(ccanvas)->drawOval(AsRect(*crect), AsPaint(*cpaint));
@@ skipping 137 matching lines @@
     sk_image_t* cimage = sk_surface_new_image_snapshot(csurface);
     
     // HERE WE CROSS THE C..C++ boundary
     canvas->drawImage((const SkImage*)cimage, 20, 20, NULL);
     
     sk_path_delete(cpath);
     sk_paint_delete(cpaint);
     sk_image_unref(cimage);
     sk_surface_unref(csurface);
 }