Change SkPicture::draw to playback

R=reed@google.com

Author: robertphillips@google.com

Review URL: https://codereview.chromium.org/540963002
diff --git a/src/core/SkCanvas.cpp b/src/core/SkCanvas.cpp
index 83fe140..3d2fc8c 100644
--- a/src/core/SkCanvas.cpp
+++ b/src/core/SkCanvas.cpp
@@ -2455,7 +2455,7 @@
 
     SkAutoCanvasMatrixPaint acmp(this, matrix, paint, picture->cullRect());
 
-    picture->draw(this);
+    picture->playback(this);
 }
 
 ///////////////////////////////////////////////////////////////////////////////