Make EXT_TILE compatible with TILE_GROUPS

Added a 1-bit flag 'large_scale_tile'. If it is 0 that is the default value,
use normal tile coding in TILE_GROUPS. If it is 1, use large-scale tile
coding in EXT_TILE.

At large_scale_tile=1 case, if single-tile-decoding is required, then the
loopfilter is disabled.

Related API and unit tests were modified.

Change-Id: I3ba12dc3d80ccf1ab21543ab3b16c02282c34e3b
diff --git a/test/superframe_test.cc b/test/superframe_test.cc
index aa41b08..17848bb 100644
--- a/test/superframe_test.cc
+++ b/test/superframe_test.cc
@@ -103,7 +103,9 @@
 TEST_P(SuperframeTest, TestSuperframeIndexIsOptional) {
   sf_count_max_ = 0;  // early exit on successful test.
   cfg_.g_lag_in_frames = 25;
-
+#if CONFIG_EXT_TILE
+  cfg_.large_scale_tile = 1;
+#endif  // CONFIG_EXT_TILE
   ::libaom_test::I420VideoSource video("hantro_collage_w352h288.yuv", 352, 288,
                                        30, 1, 0, 40);
   ASSERT_NO_FATAL_FAILURE(RunLoop(&video));