add matrix options to drawDrawable

src/core/SkDrawable.cpp

Index: src/core/SkDrawable.cpp
diff --git a/src/core/SkDrawable.cpp b/src/core/SkDrawable.cpp
index 64fefd2f1c6bba9a771c8882f071b9ad01f2c577..41547ee697612522a4c315734175eff93ce13a45 100644
--- a/src/core/SkDrawable.cpp
+++ b/src/core/SkDrawable.cpp
@@ -32,8 +32,11 @@ static void draw_bbox(SkCanvas* canvas, const SkRect& r) {
     canvas->drawLine(r.left(), r.bottom(), r.right(), r.top(), paint);
 }
 
-void SkDrawable::draw(SkCanvas* canvas) {
+void SkDrawable::draw(SkCanvas* canvas, const SkMatrix* matrix) {
     SkAutoCanvasRestore acr(canvas, true);
+    if (matrix) {
+        canvas->concat(*matrix);
+    }
     this->onDraw(canvas);
 
     if (false) {
@@ -41,6 +44,11 @@ void SkDrawable::draw(SkCanvas* canvas) {
     }
 }
 
+void SkDrawable::draw(SkCanvas* canvas, SkScalar x, SkScalar y) {
+    SkMatrix matrix = SkMatrix::MakeTrans(x, y);
+    this->draw(canvas, &matrix);
+}
+
 SkPicture* SkDrawable::newPictureSnapshot() {
     return this->onNewPictureSnapshot();
 }