Remove SkTileGrid (except for TileGridInfo).

TBR=reed@google.com

BUG=skia:3085

Review URL: https://codereview.chromium.org/845623002
diff --git a/tests/RecordingXfermodeTest.cpp b/tests/RecordingXfermodeTest.cpp
index 1835673..7c234ad 100644
--- a/tests/RecordingXfermodeTest.cpp
+++ b/tests/RecordingXfermodeTest.cpp
@@ -107,8 +107,7 @@
     virtual const SkBitmap& recordAndReplay(const Drawer& drawer,
                                             const SkRect& intoClip,
                                             SkXfermode::Mode mode) {
-        SkTileGridFactory::TileGridInfo tileGridInfo = { {100,100}, {0,0}, {0,0} };
-        SkTileGridFactory factory(tileGridInfo);
+        SkRTreeFactory factory;
         SkPictureRecorder recorder;
         SkRect canvasRect(SkRect::MakeWH(SkIntToScalar(fWidth),SkIntToScalar(fHeight)));
         SkCanvas* canvas = recorder.beginRecording(SkIntToScalar(fWidth),