Revert of Reduce buggy usage of the registry controlled domain service.

net/base/registry_controlled_domains/registry_controlled_domain.cc

Index: net/base/registry_controlled_domains/registry_controlled_domain.cc
diff --git a/net/base/registry_controlled_domains/registry_controlled_domain.cc b/net/base/registry_controlled_domains/registry_controlled_domain.cc
index 645a4f2132571886bd5bb25c26a2fcccfe692f08..607d735f3080be6b37354b5963064df6e78bd7fa 100644
--- a/net/base/registry_controlled_domains/registry_controlled_domain.cc
+++ b/net/base/registry_controlled_domains/registry_controlled_domain.cc
@@ -66,19 +66,10 @@
 const unsigned char* g_graph = kDafsa;
 size_t g_graph_length = sizeof(kDafsa);
 
-struct MappedHostComponent {
-  size_t original_begin;
-  size_t original_end;
-
-  size_t canonical_begin;
-  size_t canonical_end;
-};
-
 size_t GetRegistryLengthImpl(base::StringPiece host,
                              UnknownRegistryFilter unknown_filter,
                              PrivateRegistryFilter private_filter) {
-  if (host.empty())
-    return std::string::npos;
+  DCHECK(!host.empty());
 
   // Skip leading dots.
   const size_t host_check_begin = host.find_first_not_of('.');
@@ -198,117 +189,6 @@
   return GetDomainAndRegistryImpl(host, filter);
 }
 
-// These two functions append the given string as-is to the given output,
-// converting to UTF-8 if necessary.
-void AppendInvalidString(base::StringPiece str, url::CanonOutput* output) {
-  output->Append(str.data(), static_cast<int>(str.length()));
-}
-void AppendInvalidString(base::StringPiece16 str, url::CanonOutput* output) {
-  std::string utf8 = base::UTF16ToUTF8(str);
-  output->Append(utf8.data(), static_cast<int>(utf8.length()));
-}
-
-// Backend for PermissiveGetHostRegistryLength that handles both UTF-8 and
-// UTF-16 input. The template type is the std::string type to use (it makes the
-// typedefs easier than using the character type).
-template <typename Str>
-size_t DoPermissiveGetHostRegistryLength(base::BasicStringPiece<Str> host,
-                                         UnknownRegistryFilter unknown_filter,
-                                         PrivateRegistryFilter private_filter) {
-  std::string canonical_host;  // Do not modify outside of canon_output.
-  canonical_host.reserve(host.length());
-  url::StdStringCanonOutput canon_output(&canonical_host);
-
-  std::vector<MappedHostComponent> components;
-
-  for (size_t current = 0; current < host.length(); current++) {
-    size_t begin = current;
-
-    // Advance to next "." or end.
-    current = host.find('.', begin);
-    if (current == std::string::npos)
-      current = host.length();
-
-    MappedHostComponent mapping;
-    mapping.original_begin = begin;
-    mapping.original_end = current;
-    mapping.canonical_begin = static_cast<size_t>(canon_output.length());
-
-    // Try to append the canonicalized version of this component.
-    int current_len = static_cast<int>(current - begin);
-    if (!url::CanonicalizeHostSubstring(
-            host.data(), url::Component(static_cast<int>(begin), current_len),
-            &canon_output)) {
-      // Failed to canonicalize this component; append as-is.
-      AppendInvalidString(host.substr(begin, current_len), &canon_output);
-    }
-
-    mapping.canonical_end = static_cast<size_t>(canon_output.length());
-    components.push_back(mapping);
-
-    if (current < host.length())
-      canon_output.push_back('.');
-  }
-  canon_output.Complete();
-
-  size_t canonical_rcd_len =
-      GetRegistryLengthImpl(canonical_host, unknown_filter, private_filter);
-  if (canonical_rcd_len == 0 || canonical_rcd_len == std::string::npos)
-    return canonical_rcd_len;  // Error or no registry controlled domain.
-
-  // Find which host component the result started in.
-  size_t canonical_rcd_begin = canonical_host.length() - canonical_rcd_len;
-  for (const auto& mapping : components) {
-    // In the common case, GetRegistryLengthImpl will identify the beginning
-    // of a component and we can just return where that component was in the
-    // original string.
-    if (canonical_rcd_begin == mapping.canonical_begin)
-      return host.length() - mapping.original_begin;
-
-    if (canonical_rcd_begin >= mapping.canonical_end)
-      continue;
-
-    // The registry controlled domain begin was identified as being in the
-    // middle of this dot-separated domain component in the non-canonical
-    // input. This indicates some form of escaped dot, or a non-ASCII
-    // character that was canonicalized to a dot.
-    //
-    // Brute-force search from the end by repeatedly canonicalizing longer
-    // substrings until we get a match for the canonicalized version. This
-    // can't be done with binary search because canonicalization might increase
-    // or decrease the length of the produced string depending on where it's
-    // split. This depends on the canonicalization process not changing the
-    // order of the characters. Punycode can change the order of characters,
-    // but it doesn't work across dots so this is safe.
-
-    // Expected canonical registry controlled domain.
-    base::StringPiece canonical_rcd(&canonical_host[canonical_rcd_begin],
-                                    canonical_rcd_len);
-
-    for (int current_try = static_cast<int>(mapping.original_end) - 1;
-         current_try >= static_cast<int>(mapping.original_begin);
-         current_try--) {
-      std::string try_string;
-      url::StdStringCanonOutput try_output(&try_string);
-
-      if (!url::CanonicalizeHostSubstring(
-              host.data(),
-              url::Component(
-                  current_try,
-                  static_cast<int>(mapping.original_end) - current_try),
-              &try_output))
-        continue;  // Invalid substring, skip.
-
-      try_output.Complete();
-      if (try_string == canonical_rcd)
-        return host.length() - current_try;
-    }
-  }
-
-  NOTREACHED();
-  return canonical_rcd_len;
-}
-
 }  // namespace
 
 std::string GetDomainAndRegistry(const GURL& gurl,
@@ -358,63 +238,24 @@
     const GURL& gurl,
     UnknownRegistryFilter unknown_filter,
     PrivateRegistryFilter private_filter) {
-  return GetRegistryLengthImpl(gurl.host_piece(), unknown_filter,
-                               private_filter);
-}
-
-bool HostHasRegistryControlledDomain(base::StringPiece host,
-                                     UnknownRegistryFilter unknown_filter,
-                                     PrivateRegistryFilter private_filter) {
+  base::StringPiece host = gurl.host_piece();
+  if (host.empty())
+    return std::string::npos;
+  if (gurl.HostIsIPAddress())
+    return 0;
+  return GetRegistryLengthImpl(host, unknown_filter, private_filter);
+}
+
+size_t GetRegistryLength(base::StringPiece host,
+                         UnknownRegistryFilter unknown_filter,
+                         PrivateRegistryFilter private_filter) {
   url::CanonHostInfo host_info;
   const std::string canon_host(CanonicalizeHost(host, &host_info));
-
-  size_t rcd_length;
-  switch (host_info.family) {
-    case url::CanonHostInfo::IPV4:
-    case url::CanonHostInfo::IPV6:
-      // IP addresses don't have R.C.D.'s.
-      return false;
-    case url::CanonHostInfo::BROKEN:
-      // Host is not canonicalizable. Fall back to the slower "permissive"
-      // version.
-      rcd_length =
-          PermissiveGetHostRegistryLength(host, unknown_filter, private_filter);
-      break;
-    case url::CanonHostInfo::NEUTRAL:
-      rcd_length =
-          GetRegistryLengthImpl(canon_host, unknown_filter, private_filter);
-      break;
-    default:
-      NOTREACHED();
-      return false;
-  }
-  return (rcd_length != 0) && (rcd_length != std::string::npos);
-}
-
-size_t GetCanonicalHostRegistryLength(base::StringPiece canon_host,
-                                      UnknownRegistryFilter unknown_filter,
-                                      PrivateRegistryFilter private_filter) {
-#ifndef NDEBUG
-  // Ensure passed-in host name is canonical.
-  url::CanonHostInfo host_info;
-  DCHECK_EQ(net::CanonicalizeHost(canon_host, &host_info), canon_host);
-#endif
-
+  if (canon_host.empty())
+    return std::string::npos;
+  if (host_info.IsIPAddress())
+    return 0;
   return GetRegistryLengthImpl(canon_host, unknown_filter, private_filter);
-}
-
-size_t PermissiveGetHostRegistryLength(base::StringPiece host,
-                                       UnknownRegistryFilter unknown_filter,
-                                       PrivateRegistryFilter private_filter) {
-  return DoPermissiveGetHostRegistryLength<std::string>(host, unknown_filter,
-                                                        private_filter);
-}
-
-size_t PermissiveGetHostRegistryLength(base::StringPiece16 host,
-                                       UnknownRegistryFilter unknown_filter,
-                                       PrivateRegistryFilter private_filter) {
-  return DoPermissiveGetHostRegistryLength<base::string16>(host, unknown_filter,
-                                                           private_filter);
 }
 
 void SetFindDomainGraph() {