Add tiled rendering option to viewer

Bug: skia:
Change-Id: I4bb5e0107d06798040a37609499b4e2b48cf7e29
Reviewed-on: https://skia-review.googlesource.com/c/172962
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Osman <brianosman@google.com>
diff --git a/tools/viewer/Viewer.h b/tools/viewer/Viewer.h
index f2fd3e7..eace2e9 100644
--- a/tools/viewer/Viewer.h
+++ b/tools/viewer/Viewer.h
@@ -159,6 +159,10 @@
     // identity unless the window initially scales the content to fit the screen.
     SkMatrix               fDefaultMatrix;
 
+    bool                   fTiled;
+    bool                   fDrawTileBoundaries;
+    SkSize                 fTileScale;
+
     enum PerspectiveMode {
         kPerspective_Off,
         kPerspective_Real,