Small formatting and style changes

src/core/ext/transport/chttp2/transport/hpack_encoder.cc

@@ -690,7 +690,7 @@ void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor* c,
   for (size_t i = 0; i < extra_headers_size; ++i) {
     grpc_mdelem md = *extra_headers[i];
     uint8_t static_index = GRPC_MDINDEX(md);
-    if (static_index > 0) {
+    if (static_index != GRPC_MDINDEX_UNUSED) {
       emit_indexed(c, static_index, &st);
     } else {
       hpack_enc(c, md, &st);
@@ -699,7 +699,7 @@ void grpc_chttp2_encode_header(grpc_chttp2_hpack_compressor* c,
   grpc_metadata_batch_assert_ok(metadata);
   for (grpc_linked_mdelem* l = metadata->list.head; l; l = l->next) {
     uint8_t static_index = GRPC_MDINDEX(l->md);
-    if (static_index > 0) {
+    if (static_index != GRPC_MDINDEX_UNUSED) {
       emit_indexed(c, static_index, &st);
     } else {
       hpack_enc(c, l->md, &st);

src/core/lib/transport/metadata_batch.cc

@@ -109,7 +109,6 @@ static grpc_error* maybe_link_callout(grpc_metadata_batch* batch,
     batch->idx.array[idx] = storage;
     return GRPC_ERROR_NONE;
   }
-
   return grpc_attach_md_to_error(
       GRPC_ERROR_CREATE_FROM_STATIC_STRING("Unallowed duplicate metadata"),
       storage->md);

src/core/lib/transport/static_metadata.cc

@@ -24,7 +24,7 @@
  * an explanation of what's going on.
  */
 
-#include <grpc/impl/codegen/port_platform.h>
+#include <grpc/support/port_platform.h>
 
 #include "src/core/lib/transport/static_metadata.h"
 

src/core/lib/transport/static_metadata.h

@@ -27,7 +27,7 @@
 #ifndef GRPC_CORE_LIB_TRANSPORT_STATIC_METADATA_H
 #define GRPC_CORE_LIB_TRANSPORT_STATIC_METADATA_H
 
-#include <grpc/impl/codegen/port_platform.h>
+#include <grpc/support/port_platform.h>
 
 #include "src/core/lib/transport/metadata.h"
 

tools/codegen/core/gen_static_metadata.py

@@ -367,12 +367,12 @@ an explanation of what's going on.
 print >> H, '#ifndef GRPC_CORE_LIB_TRANSPORT_STATIC_METADATA_H'
 print >> H, '#define GRPC_CORE_LIB_TRANSPORT_STATIC_METADATA_H'
 print >> H
-print >> H, '#include <grpc/impl/codegen/port_platform.h>'
+print >> H, '#include <grpc/support/port_platform.h>'
 print >> H
 print >> H, '#include "src/core/lib/transport/metadata.h"'
 print >> H
 
-print >> C, '#include <grpc/impl/codegen/port_platform.h>'
+print >> C, '#include <grpc/support/port_platform.h>'
 print >> C
 print >> C, '#include "src/core/lib/transport/static_metadata.h"'
 print >> C