Expose av1_loop_restoration_filter_unit in restoration.h

This patch also does a certain amount of rejigging for loop
restoration coefficients, grouping the information for a given
restoration unit into a structure called RestorationUnitInfo. The end
result is to completely dispense with the RestorationInternal
structure.

The copy_tile functions in restoration.c, together with those
functions that operate on a single stripe, have been changed so that
they take pointers to the top-left corner of the area on which they
should work, together with a width and height.

The same isn't true of av1_loop_restoration_filter_unit, which still
takes pointers to the top-left of the tile. This is because you
actually need the absolute position in the tile in order to do striped
loop restoration properly.

Change-Id: I768c182cd15c9b2d6cfabb5ffca697cd2a3ff9e1
diff --git a/av1/common/alloccommon.c b/av1/common/alloccommon.c
index a7a2c5c..0bd26a7 100644
--- a/av1/common/alloccommon.c
+++ b/av1/common/alloccommon.c
@@ -162,8 +162,9 @@
     int buf_size = num_stripes * 2 * stride;
     uint8_t *above_buf, *below_buf;
 
-    aom_free(cm->rst_info[p].stripe_boundary_above);
-    aom_free(cm->rst_info[p].stripe_boundary_below);
+    RestorationStripeBoundaries *boundaries = &cm->rst_info[p].boundaries;
+    aom_free(boundaries->stripe_boundary_above);
+    aom_free(boundaries->stripe_boundary_below);
 
 #if CONFIG_HIGHBITDEPTH
     if (cm->use_highbitdepth) buf_size = buf_size * 2;
@@ -172,9 +173,9 @@
                     (uint8_t *)aom_memalign(1 << align_bits, buf_size));
     CHECK_MEM_ERROR(cm, below_buf,
                     (uint8_t *)aom_memalign(1 << align_bits, buf_size));
-    cm->rst_info[p].stripe_boundary_above = above_buf;
-    cm->rst_info[p].stripe_boundary_below = below_buf;
-    cm->rst_info[p].stripe_boundary_stride = stride;
+    boundaries->stripe_boundary_above = above_buf;
+    boundaries->stripe_boundary_below = below_buf;
+    boundaries->stripe_boundary_stride = stride;
   }
 #endif  // CONFIG_STRIPED_LOOP_RESTORATION
 }