misc-fix: use enum for reset_frame_context consts

This commit merge the fixes that address the issues with the syntax
element reset_frame_context, and the conflict between frame_parallel_
decoding_mode and refresh_frame_context.

Related tracking issue:
https://bugs.chromium.org/p/webm/issues/detail?id=1030
Original libvpx commit:
62da0bf162f369cd99f2ffe37e4cb21810422e37
d1474f02aaf324112e63879b12c0f61553eed2a8

Change-Id: Iff0369c272d5eca5207b307a70911965a1f2f404

av1/decoder/decodeframe.c

diff --git a/av1/decoder/decodeframe.c b/av1/decoder/decodeframe.c
index 5f11723..8f8d3f6 100644
--- a/av1/decoder/decodeframe.c
+++ b/av1/decoder/decodeframe.c
@@ -1762,7 +1762,6 @@
     if (cm->error_resilient_mode) {
       cm->reset_frame_context = RESET_FRAME_CONTEXT_ALL;
     } else {
-#if CONFIG_MISC_FIXES
       if (cm->intra_only) {
         cm->reset_frame_context = aom_rb_read_bit(rb)
                                       ? RESET_FRAME_CONTEXT_ALL
@@ -1776,15 +1775,6 @@
                                         ? RESET_FRAME_CONTEXT_ALL
                                         : RESET_FRAME_CONTEXT_CURRENT;
       }
-#else
-      static const RESET_FRAME_CONTEXT_MODE reset_frame_context_conv_tbl[4] = {
-        RESET_FRAME_CONTEXT_NONE, RESET_FRAME_CONTEXT_NONE,
-        RESET_FRAME_CONTEXT_CURRENT, RESET_FRAME_CONTEXT_ALL
-      };
-
-      cm->reset_frame_context =
-          reset_frame_context_conv_tbl[aom_rb_read_literal(rb, 2)];
-#endif
     }
 
     if (cm->intra_only) {
@@ -1870,10 +1860,6 @@
       cm->refresh_frame_context = aom_rb_read_bit(rb)
                                       ? REFRESH_FRAME_CONTEXT_FORWARD
                                       : REFRESH_FRAME_CONTEXT_BACKWARD;
-#if !CONFIG_MISC_FIXES
-    } else {
-      aom_rb_read_bit(rb);  // parallel decoding mode flag
-#endif
     }
   } else {
     cm->refresh_frame_context = REFRESH_FRAME_CONTEXT_OFF;

av1/encoder/bitstream.c

diff --git a/av1/encoder/bitstream.c b/av1/encoder/bitstream.c
index c3589d3..06d55d9 100644
--- a/av1/encoder/bitstream.c
+++ b/av1/encoder/bitstream.c
@@ -2003,7 +2003,6 @@
     if (!cm->show_frame) aom_wb_write_bit(wb, cm->intra_only);
 
     if (!cm->error_resilient_mode) {
-#if CONFIG_MISC_FIXES
       if (cm->intra_only) {
         aom_wb_write_bit(wb,
                          cm->reset_frame_context == RESET_FRAME_CONTEXT_ALL);
@@ -2014,12 +2013,6 @@
           aom_wb_write_bit(wb,
                            cm->reset_frame_context == RESET_FRAME_CONTEXT_ALL);
       }
-#else
-      static const int reset_frame_context_conv_tbl[3] = { 0, 2, 3 };
-
-      aom_wb_write_literal(
-          wb, reset_frame_context_conv_tbl[cm->reset_frame_context], 2);
-#endif
     }
 
 #if CONFIG_EXT_REFS
@@ -2080,9 +2073,7 @@
   if (!cm->error_resilient_mode) {
     aom_wb_write_bit(wb,
                      cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_OFF);
-#if CONFIG_MISC_FIXES
     if (cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_OFF)
-#endif
       aom_wb_write_bit(
           wb, cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_BACKWARD);
   }