Install a hook to swap between SkPicture backends with a single define.

src/core/SkPictureRecorder.cpp

Index: src/core/SkPictureRecorder.cpp
diff --git a/src/core/SkPictureRecorder.cpp b/src/core/SkPictureRecorder.cpp
index 7d24caf6fce880f9e32a2dec6c7de0e11c8e7d8a..d90f8852f8f3c9a55bb63a4f7ec42a15761ed662 100644
--- a/src/core/SkPictureRecorder.cpp
+++ b/src/core/SkPictureRecorder.cpp
@@ -20,6 +20,16 @@ SkPictureRecorder::~SkPictureRecorder() {}
 SkCanvas* SkPictureRecorder::beginRecording(int width, int height,
                                             SkBBHFactory* bbhFactory /* = NULL */,
                                             uint32_t recordFlags /* = 0 */) {
+#ifdef SK_PICTURE_USE_SK_RECORD
+    return EXPERIMENTAL_beginRecording(width, height, bbhFactory);
+#else
+    return DEPRECATED_beginRecording(width, height, bbhFactory, recordFlags);
+#endif
+}
+
+SkCanvas* SkPictureRecorder::DEPRECATED_beginRecording(int width, int height,
+                                                       SkBBHFactory* bbhFactory /* = NULL */,
+                                                       uint32_t recordFlags /* = 0 */) {
     fWidth = width;
     fHeight = height;