Update remaining spec links for signed-exchanges

This is a follow-up to crrev.com/c/981813.
- Update spec links to the implementation checkpoint
- Use #section-name instead of #rfc.section.numbers as numbers may change
- Remove unused constants from signed_exchange_consts.h

Bug: 803774
Change-Id: I460d580f30275c6a586cee4b1c7540ff80a98791
Reviewed-on: https://chromium-review.googlesource.com/981874Reviewed-by: Kouhei Ueno <kouhei@chromium.org>
Reviewed-by: Tsuyoshi Horo <horo@chromium.org>
Commit-Queue: Kunihiko Sakamoto <ksakamoto@chromium.org>
Cr-Commit-Position: refs/heads/master@{#546056}

content/browser/web_package/signed_exchange_consts.h

@@ -10,18 +10,14 @@ namespace content {
 constexpr char kAcceptHeaderSignedExchangeSuffix[] =
     ",application/signed-exchange;v=b0";
 
-// Field names defined in the application/http-exchange+cbor content type:
-// https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#rfc.section.5
+// Field names defined in the application/signed-exchange content type:
+// https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#application-signed-exchange
 
 constexpr char kCertSha256Key[] = "certSha256";
 constexpr char kDateKey[] = "date";
 constexpr char kExpiresKey[] = "expires";
 constexpr char kHeadersKey[] = "headers";
-constexpr char kHtxg[] = "htxg";
 constexpr char kMethodKey[] = ":method";
-constexpr char kPayload[] = "payload";
-constexpr char kRequest[] = "request";
-constexpr char kResponse[] = "response";
 constexpr char kSignature[] = "signature";
 constexpr char kStatusKey[] = ":status";
 constexpr char kUrlKey[] = ":url";

content/browser/web_package/signed_exchange_header.cc

@@ -21,7 +21,7 @@ namespace {
 // header field. Stateful header fields will cause validation failure of
 // signed exchanges.
 // Note that |name| must be lower-cased.
-// https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#rfc.section.4.1
+// https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#stateful-headers
 bool IsStatefulRequestHeader(base::StringPiece name) {
   DCHECK_EQ(name, base::ToLowerASCII(name));
 

content/browser/web_package/signed_exchange_header.h

@@ -22,7 +22,7 @@ namespace content {
 
 // SignedExchangeHeader contains all information captured in signed exchange
 // envelope but the payload.
-// https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html
+// https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html
 class CONTENT_EXPORT SignedExchangeHeader {
  public:
   static constexpr size_t kEncodedHeaderLengthInBytes = 3;
@@ -35,10 +35,10 @@ class CONTENT_EXPORT SignedExchangeHeader {
   using HeaderMap = std::map<std::string, std::string>;
 
   // Parse headers from the application/signed-exchange;v=b0 format.
-  // https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#rfc.section.5.3
+  // https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#application-signed-exchange
   //
   // This also performs the step 3 and 4 of "Cross-origin trust" validation.
-  // https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#rfc.section.4
+  // https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#cross-origin-trust
   static base::Optional<SignedExchangeHeader> Parse(
       base::span<const uint8_t> input);
   SignedExchangeHeader();

content/browser/web_package/signed_exchange_header_parser.h

@@ -19,7 +19,7 @@
 namespace content {
 
 // Provide parsers for signed-exchange headers.
-// https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html
+// https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html
 class CONTENT_EXPORT SignedExchangeHeaderParser {
  public:
   struct CONTENT_EXPORT Signature {
@@ -40,7 +40,7 @@ class CONTENT_EXPORT SignedExchangeHeaderParser {
   };
 
   // Parses a value of the Signature header.
-  // https://wicg.github.io/webpackage/draft-yasskin-http-origin-signed-responses.html#rfc.section.3.2
+  // https://wicg.github.io/webpackage/draft-yasskin-httpbis-origin-signed-exchanges-impl.html#signature-header
   static base::Optional<std::vector<Signature>> ParseSignature(
       base::StringPiece signature_str);