Merging upstream version 126.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

8 files changed, 213 insertions, 281 deletions

diff --git a/dom/url/URL.cpp b/dom/url/URL.cpp
index 799bb72cff..1011eda210 100644
--- a/dom/url/URL.cpp
+++ b/dom/url/URL.cpp
@@ -36,8 +36,8 @@ JSObject* URL::WrapObject(JSContext* aCx, JS::Handle<JSObject*> aGivenProto) {
 
 /* static */
 already_AddRefed<URL> URL::Constructor(const GlobalObject& aGlobal,
-                                       const nsAString& aURL,
-                                       const Optional<nsAString>& aBase,
+                                       const nsACString& aURL,
+                                       const Optional<nsACString>& aBase,
                                        ErrorResult& aRv) {
   if (aBase.WasPassed()) {
     return Constructor(aGlobal.GetAsSupports(), aURL, aBase.Value(), aRv);
@@ -48,20 +48,13 @@ already_AddRefed<URL> URL::Constructor(const GlobalObject& aGlobal,
 
 /* static */
 already_AddRefed<URL> URL::Constructor(nsISupports* aParent,
-                                       const nsAString& aURL,
-                                       const nsAString& aBase,
+                                       const nsACString& aURL,
+                                       const nsACString& aBase,
                                        ErrorResult& aRv) {
-  // Don't use NS_ConvertUTF16toUTF8 because that doesn't let us handle OOM.
-  nsAutoCString base;
-  if (!AppendUTF16toUTF8(aBase, base, fallible)) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
-    return nullptr;
-  }
-
   nsCOMPtr<nsIURI> baseUri;
-  nsresult rv = NS_NewURI(getter_AddRefs(baseUri), base);
+  nsresult rv = NS_NewURI(getter_AddRefs(baseUri), aBase);
   if (NS_WARN_IF(NS_FAILED(rv))) {
-    aRv.ThrowTypeError<MSG_INVALID_URL>(base);
+    aRv.ThrowTypeError<MSG_INVALID_URL>(aBase);
     return nullptr;
   }
 
@@ -70,21 +63,14 @@ already_AddRefed<URL> URL::Constructor(nsISupports* aParent,
 
 /* static */
 already_AddRefed<URL> URL::Constructor(nsISupports* aParent,
-                                       const nsAString& aURL, nsIURI* aBase,
+                                       const nsACString& aURL, nsIURI* aBase,
                                        ErrorResult& aRv) {
-  // Don't use NS_ConvertUTF16toUTF8 because that doesn't let us handle OOM.
-  nsAutoCString urlStr;
-  if (!AppendUTF16toUTF8(aURL, urlStr, fallible)) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
-    return nullptr;
-  }
-
   nsCOMPtr<nsIURI> uri;
-  nsresult rv = NS_NewURI(getter_AddRefs(uri), urlStr, nullptr, aBase);
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aURL, nullptr, aBase);
   if (NS_FAILED(rv)) {
     // No need to warn in this case. It's common to use the URL constructor
     // to determine if a URL is valid and an exception will be propagated.
-    aRv.ThrowTypeError<MSG_INVALID_URL>(urlStr);
+    aRv.ThrowTypeError<MSG_INVALID_URL>(aURL);
     return nullptr;
   }
 
@@ -96,7 +82,7 @@ already_AddRefed<URL> URL::FromURI(GlobalObject& aGlobal, nsIURI* aURI) {
 }
 
 void URL::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                          nsAString& aResult, ErrorResult& aRv) {
+                          nsACString& aResult, ErrorResult& aRv) {
   if (NS_IsMainThread()) {
     URLMainThread::CreateObjectURL(aGlobal, aBlob, aResult, aRv);
   } else {
@@ -105,12 +91,12 @@ void URL::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
 }
 
 void URL::CreateObjectURL(const GlobalObject& aGlobal, MediaSource& aSource,
-                          nsAString& aResult, ErrorResult& aRv) {
+                          nsACString& aResult, ErrorResult& aRv) {
   MOZ_ASSERT(NS_IsMainThread());
   URLMainThread::CreateObjectURL(aGlobal, aSource, aResult, aRv);
 }
 
-void URL::RevokeObjectURL(const GlobalObject& aGlobal, const nsAString& aURL,
+void URL::RevokeObjectURL(const GlobalObject& aGlobal, const nsACString& aURL,
                           ErrorResult& aRv) {
   if (aURL.Contains('#')) {
     // Don't revoke URLs that contain fragments.
@@ -124,7 +110,7 @@ void URL::RevokeObjectURL(const GlobalObject& aGlobal, const nsAString& aURL,
   }
 }
 
-bool URL::IsValidObjectURL(const GlobalObject& aGlobal, const nsAString& aURL,
+bool URL::IsValidObjectURL(const GlobalObject& aGlobal, const nsACString& aURL,
                            ErrorResult& aRv) {
   if (NS_IsMainThread()) {
     return URLMainThread::IsValidObjectURL(aGlobal, aURL, aRv);
@@ -132,32 +118,40 @@ bool URL::IsValidObjectURL(const GlobalObject& aGlobal, const nsAString& aURL,
   return URLWorker::IsValidObjectURL(aGlobal, aURL, aRv);
 }
 
-bool URL::CanParse(const GlobalObject& aGlobal, const nsAString& aURL,
-                   const Optional<nsAString>& aBase) {
+already_AddRefed<nsIURI> URL::ParseURI(const nsACString& aURL,
+                                       const Optional<nsACString>& aBase) {
   nsCOMPtr<nsIURI> baseUri;
-  if (aBase.WasPassed()) {
-    // Don't use NS_ConvertUTF16toUTF8 because that doesn't let us handle OOM.
-    nsAutoCString base;
-    if (!AppendUTF16toUTF8(aBase.Value(), base, fallible)) {
-      // Just return false with OOM errors as no ErrorResult.
-      return false;
-    }
+  nsCOMPtr<nsIURI> uri;
 
-    nsresult rv = NS_NewURI(getter_AddRefs(baseUri), base);
+  if (aBase.WasPassed()) {
+    nsresult rv = NS_NewURI(getter_AddRefs(baseUri), aBase.Value());
     if (NS_FAILED(rv)) {
-      // Invalid base URL, return false.
-      return false;
+      return nullptr;
     }
   }
 
-  nsAutoCString urlStr;
-  if (!AppendUTF16toUTF8(aURL, urlStr, fallible)) {
-    // Just return false with OOM errors as no ErrorResult.
-    return false;
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aURL, nullptr, baseUri);
+  if (NS_FAILED(rv)) {
+    return nullptr;
   }
 
-  nsCOMPtr<nsIURI> uri;
-  return NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), urlStr, nullptr, baseUri));
+  return uri.forget();
+};
+
+already_AddRefed<URL> URL::Parse(const GlobalObject& aGlobal,
+                                 const nsACString& aURL,
+                                 const Optional<nsACString>& aBase) {
+  nsCOMPtr<nsIURI> uri = ParseURI(aURL, aBase);
+  if (!uri) {
+    return nullptr;
+  }
+  return MakeAndAddRef<URL>(aGlobal.GetAsSupports(), std::move(uri));
+}
+
+bool URL::CanParse(const GlobalObject& aGlobal, const nsACString& aURL,
+                   const Optional<nsACString>& aBase) {
+  nsCOMPtr<nsIURI> uri = ParseURI(aURL, aBase);
+  return !!uri;
 }
 
 URLSearchParams* URL::SearchParams() {
@@ -174,7 +168,7 @@ void URL::CreateSearchParamsIfNeeded() {
   }
 }
 
-void URL::SetSearch(const nsAString& aSearch) {
+void URL::SetSearch(const nsACString& aSearch) {
   SetSearchInternal(aSearch);
   UpdateURLSearchParams();
 }
@@ -183,35 +177,22 @@ void URL::URLSearchParamsUpdated(URLSearchParams* aSearchParams) {
   MOZ_ASSERT(mSearchParams);
   MOZ_ASSERT(mSearchParams == aSearchParams);
 
-  nsAutoString search;
+  nsAutoCString search;
   mSearchParams->Serialize(search);
-
   SetSearchInternal(search);
 }
 
-#define URL_GETTER(value, func)  \
-  MOZ_ASSERT(mURI);              \
-  value.Truncate();              \
-  nsAutoCString tmp;             \
-  nsresult rv = mURI->func(tmp); \
-  if (NS_SUCCEEDED(rv)) {        \
-    CopyUTF8toUTF16(tmp, value); \
-  }
-
-void URL::GetHref(nsAString& aHref) const { URL_GETTER(aHref, GetSpec); }
+#define URL_GETTER(value, func) \
+  MOZ_ASSERT(mURI);             \
+  mURI->func(value);
 
-void URL::SetHref(const nsAString& aHref, ErrorResult& aRv) {
-  // Don't use NS_ConvertUTF16toUTF8 because that doesn't let us handle OOM.
-  nsAutoCString href;
-  if (!AppendUTF16toUTF8(aHref, href, fallible)) {
-    aRv.Throw(NS_ERROR_OUT_OF_MEMORY);
-    return;
-  }
+void URL::GetHref(nsACString& aHref) const { URL_GETTER(aHref, GetSpec); }
 
+void URL::SetHref(const nsACString& aHref, ErrorResult& aRv) {
   nsCOMPtr<nsIURI> uri;
-  nsresult rv = NS_NewURI(getter_AddRefs(uri), href);
+  nsresult rv = NS_NewURI(getter_AddRefs(uri), aHref);
   if (NS_FAILED(rv)) {
-    aRv.ThrowTypeError<MSG_INVALID_URL>(href);
+    aRv.ThrowTypeError<MSG_INVALID_URL>(aHref);
     return;
   }
 
@@ -219,7 +200,7 @@ void URL::SetHref(const nsAString& aHref, ErrorResult& aRv) {
   UpdateURLSearchParams();
 }
 
-void URL::GetOrigin(nsAString& aOrigin) const {
+void URL::GetOrigin(nsACString& aOrigin) const {
   nsresult rv =
       nsContentUtils::GetWebExposedOriginSerialization(URI(), aOrigin);
   if (NS_WARN_IF(NS_FAILED(rv))) {
@@ -227,12 +208,12 @@ void URL::GetOrigin(nsAString& aOrigin) const {
   }
 }
 
-void URL::GetProtocol(nsAString& aProtocol) const {
+void URL::GetProtocol(nsACString& aProtocol) const {
   URL_GETTER(aProtocol, GetScheme);
   aProtocol.Append(char16_t(':'));
 }
 
-void URL::SetProtocol(const nsAString& aProtocol) {
+void URL::SetProtocol(const nsACString& aProtocol) {
   nsCOMPtr<nsIURI> uri(URI());
   if (!uri) {
     return;
@@ -244,81 +225,67 @@ void URL::SetProtocol(const nsAString& aProtocol) {
   mURI = std::move(uri);
 }
 
-void URL::GetUsername(nsAString& aUsername) const {
+void URL::GetUsername(nsACString& aUsername) const {
   URL_GETTER(aUsername, GetUsername);
 }
 
-void URL::SetUsername(const nsAString& aUsername) {
+void URL::SetUsername(const nsACString& aUsername) {
   MOZ_ASSERT(mURI);
-
-  Unused << NS_MutateURI(mURI)
-                .SetUsername(NS_ConvertUTF16toUTF8(aUsername))
-                .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetUsername(aUsername).Finalize(mURI);
 }
 
-void URL::GetPassword(nsAString& aPassword) const {
+void URL::GetPassword(nsACString& aPassword) const {
   URL_GETTER(aPassword, GetPassword);
 }
 
-void URL::SetPassword(const nsAString& aPassword) {
+void URL::SetPassword(const nsACString& aPassword) {
   MOZ_ASSERT(mURI);
 
-  Unused << NS_MutateURI(mURI)
-                .SetPassword(NS_ConvertUTF16toUTF8(aPassword))
-                .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetPassword(aPassword).Finalize(mURI);
 }
 
-void URL::GetHost(nsAString& aHost) const { URL_GETTER(aHost, GetHostPort); }
+void URL::GetHost(nsACString& aHost) const { URL_GETTER(aHost, GetHostPort); }
 
-void URL::SetHost(const nsAString& aHost) {
+void URL::SetHost(const nsACString& aHost) {
   MOZ_ASSERT(mURI);
-
-  Unused << NS_MutateURI(mURI)
-                .SetHostPort(NS_ConvertUTF16toUTF8(aHost))
-                .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetHostPort(aHost).Finalize(mURI);
 }
 
-void URL::GetHostname(nsAString& aHostname) const {
+void URL::GetHostname(nsACString& aHostname) const {
   MOZ_ASSERT(mURI);
-
   aHostname.Truncate();
   nsContentUtils::GetHostOrIPv6WithBrackets(mURI, aHostname);
 }
 
-void URL::SetHostname(const nsAString& aHostname) {
+void URL::SetHostname(const nsACString& aHostname) {
   MOZ_ASSERT(mURI);
 
   // nsStandardURL returns NS_ERROR_UNEXPECTED for an empty hostname
   // The return code is silently ignored
-  mozilla::Unused << NS_MutateURI(mURI)
-                         .SetHost(NS_ConvertUTF16toUTF8(aHostname))
-                         .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetHost(aHostname).Finalize(mURI);
 }
 
-void URL::GetPort(nsAString& aPort) const {
+void URL::GetPort(nsACString& aPort) const {
   MOZ_ASSERT(mURI);
-
   aPort.Truncate();
 
   int32_t port;
   nsresult rv = mURI->GetPort(&port);
   if (NS_SUCCEEDED(rv) && port != -1) {
-    nsAutoString portStr;
-    portStr.AppendInt(port, 10);
-    aPort.Assign(portStr);
+    aPort.AppendInt(port, 10);
   }
 }
 
-void URL::SetPort(const nsAString& aPort) {
+void URL::SetPort(const nsACString& aPort) {
   nsresult rv;
-  nsAutoString portStr(aPort);
+  nsAutoCString portStr(aPort);
   int32_t port = -1;
 
   // nsIURI uses -1 as default value.
   portStr.StripTaggedASCII(ASCIIMask::MaskCRLFTab());
   if (!portStr.IsEmpty()) {
     // To be valid, the port must start with an ASCII digit.
-    // (nsAString::ToInteger ignores leading junk, so check before calling.)
+    // (nsACString::ToInteger ignores leading junk, so check before calling.)
     if (!IsAsciiDigit(portStr[0])) {
       return;
     }
@@ -331,32 +298,21 @@ void URL::SetPort(const nsAString& aPort) {
   Unused << NS_MutateURI(mURI).SetPort(port).Finalize(mURI);
 }
 
-void URL::GetPathname(nsAString& aPathname) const {
+void URL::GetPathname(nsACString& aPathname) const {
   MOZ_ASSERT(mURI);
-
-  aPathname.Truncate();
-
   // Do not throw!  Not having a valid URI or URL should result in an empty
   // string.
-
-  nsAutoCString file;
-  nsresult rv = mURI->GetFilePath(file);
-  if (NS_SUCCEEDED(rv)) {
-    CopyUTF8toUTF16(file, aPathname);
-  }
+  mURI->GetFilePath(aPathname);
 }
 
-void URL::SetPathname(const nsAString& aPathname) {
+void URL::SetPathname(const nsACString& aPathname) {
   MOZ_ASSERT(mURI);
 
   // Do not throw!
-
-  Unused << NS_MutateURI(mURI)
-                .SetFilePath(NS_ConvertUTF16toUTF8(aPathname))
-                .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetFilePath(aPathname).Finalize(mURI);
 }
 
-void URL::GetSearch(nsAString& aSearch) const {
+void URL::GetSearch(nsACString& aSearch) const {
   MOZ_ASSERT(mURI);
 
   aSearch.Truncate();
@@ -364,44 +320,33 @@ void URL::GetSearch(nsAString& aSearch) const {
   // Do not throw!  Not having a valid URI or URL should result in an empty
   // string.
 
-  nsAutoCString search;
   nsresult rv;
-
-  rv = mURI->GetQuery(search);
-  if (NS_SUCCEEDED(rv) && !search.IsEmpty()) {
-    aSearch.Assign(u'?');
-    AppendUTF8toUTF16(search, aSearch);
+  rv = mURI->GetQuery(aSearch);
+  if (NS_SUCCEEDED(rv) && !aSearch.IsEmpty()) {
+    aSearch.Insert('?', 0);
   }
 }
 
-void URL::GetHash(nsAString& aHash) const {
+void URL::GetHash(nsACString& aHash) const {
   MOZ_ASSERT(mURI);
-
   aHash.Truncate();
-
-  nsAutoCString ref;
-  nsresult rv = mURI->GetRef(ref);
-  if (NS_SUCCEEDED(rv) && !ref.IsEmpty()) {
-    aHash.Assign(char16_t('#'));
-    AppendUTF8toUTF16(ref, aHash);
+  nsresult rv = mURI->GetRef(aHash);
+  if (NS_SUCCEEDED(rv) && !aHash.IsEmpty()) {
+    aHash.Insert('#', 0);
   }
 }
 
-void URL::SetHash(const nsAString& aHash) {
+void URL::SetHash(const nsACString& aHash) {
   MOZ_ASSERT(mURI);
 
-  Unused
-      << NS_MutateURI(mURI).SetRef(NS_ConvertUTF16toUTF8(aHash)).Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetRef(aHash).Finalize(mURI);
 }
 
-void URL::SetSearchInternal(const nsAString& aSearch) {
+void URL::SetSearchInternal(const nsACString& aSearch) {
   MOZ_ASSERT(mURI);
 
   // Ignore failures to be compatible with NS4.
-
-  Unused << NS_MutateURI(mURI)
-                .SetQuery(NS_ConvertUTF16toUTF8(aSearch))
-                .Finalize(mURI);
+  Unused << NS_MutateURI(mURI).SetQuery(aSearch).Finalize(mURI);
 }
 
 void URL::UpdateURLSearchParams() {
diff --git a/dom/url/URL.h b/dom/url/URL.h
index 7c2563d095..cf72a7be63 100644
--- a/dom/url/URL.h
+++ b/dom/url/URL.h
@@ -44,79 +44,73 @@ class URL final : public URLSearchParamsObserver, public nsWrapperCache {
                        JS::Handle<JSObject*> aGivenProto) override;
 
   static already_AddRefed<URL> Constructor(const GlobalObject& aGlobal,
-                                           const nsAString& aURL,
-                                           const Optional<nsAString>& aBase,
+                                           const nsACString& aURL,
+                                           const Optional<nsACString>& aBase,
                                            ErrorResult& aRv);
 
   static already_AddRefed<URL> Constructor(nsISupports* aParent,
-                                           const nsAString& aURL,
-                                           const nsAString& aBase,
+                                           const nsACString& aURL,
+                                           const nsACString& aBase,
                                            ErrorResult& aRv);
 
   static already_AddRefed<URL> Constructor(nsISupports* aParent,
-                                           const nsAString& aURL, nsIURI* aBase,
-                                           ErrorResult& aRv);
+                                           const nsACString& aURL,
+                                           nsIURI* aBase, ErrorResult& aRv);
 
   static void CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                              nsAString& aResult, ErrorResult& aRv);
+                              nsACString& aResult, ErrorResult& aRv);
 
   static void CreateObjectURL(const GlobalObject& aGlobal, MediaSource& aSource,
-                              nsAString& aResult, ErrorResult& aRv);
+                              nsACString& aResult, ErrorResult& aRv);
 
   static void RevokeObjectURL(const GlobalObject& aGlobal,
-                              const nsAString& aURL, ErrorResult& aRv);
+                              const nsACString& aURL, ErrorResult& aRv);
 
   static bool IsValidObjectURL(const GlobalObject& aGlobal,
-                               const nsAString& aURL, ErrorResult& aRv);
-
-  static bool CanParse(const GlobalObject& aGlobal, const nsAString& aURL,
-                       const Optional<nsAString>& aBase);
-
-  void GetHref(nsAString& aHref) const;
-
-  void SetHref(const nsAString& aHref, ErrorResult& aRv);
-
-  void GetOrigin(nsAString& aOrigin) const;
-
-  void GetProtocol(nsAString& aProtocol) const;
+                               const nsACString& aURL, ErrorResult& aRv);
 
-  void SetProtocol(const nsAString& aProtocol);
+  static already_AddRefed<URL> Parse(const GlobalObject& aGlobal,
+                                     const nsACString& aURL,
+                                     const Optional<nsACString>& aBase);
 
-  void GetUsername(nsAString& aUsername) const;
+  static bool CanParse(const GlobalObject& aGlobal, const nsACString& aURL,
+                       const Optional<nsACString>& aBase);
 
-  void SetUsername(const nsAString& aUsername);
+  void GetHref(nsACString& aHref) const;
+  void SetHref(const nsACString& aHref, ErrorResult& aRv);
 
-  void GetPassword(nsAString& aPassword) const;
+  void GetOrigin(nsACString& aOrigin) const;
 
-  void SetPassword(const nsAString& aPassword);
+  void GetProtocol(nsACString& aProtocol) const;
+  void SetProtocol(const nsACString& aProtocol);
 
-  void GetHost(nsAString& aHost) const;
+  void GetUsername(nsACString& aUsername) const;
+  void SetUsername(const nsACString& aUsername);
 
-  void SetHost(const nsAString& aHost);
+  void GetPassword(nsACString& aPassword) const;
+  void SetPassword(const nsACString& aPassword);
 
-  void GetHostname(nsAString& aHostname) const;
+  void GetHost(nsACString& aHost) const;
+  void SetHost(const nsACString& aHost);
 
-  void SetHostname(const nsAString& aHostname);
+  void GetHostname(nsACString& aHostname) const;
+  void SetHostname(const nsACString& aHostname);
 
-  void GetPort(nsAString& aPort) const;
+  void GetPort(nsACString& aPort) const;
+  void SetPort(const nsACString& aPort);
 
-  void SetPort(const nsAString& aPort);
+  void GetPathname(nsACString& aPathname) const;
+  void SetPathname(const nsACString& aPathname);
 
-  void GetPathname(nsAString& aPathname) const;
-
-  void SetPathname(const nsAString& aPathname);
-
-  void GetSearch(nsAString& aSearch) const;
-
-  void SetSearch(const nsAString& aSearch);
+  void GetSearch(nsACString& aSearch) const;
+  void SetSearch(const nsACString& aSearch);
 
   URLSearchParams* SearchParams();
 
-  void GetHash(nsAString& aHost) const;
+  void GetHash(nsACString& aHash) const;
+  void SetHash(const nsACString& aHash);
 
-  void SetHash(const nsAString& aHash);
-
-  void ToJSON(nsAString& aResult) const { GetHref(aResult); }
+  void ToJSON(nsACString& aResult) const { GetHref(aResult); }
 
   // URLSearchParamsObserver
   void URLSearchParamsUpdated(URLSearchParams* aSearchParams) override;
@@ -127,10 +121,13 @@ class URL final : public URLSearchParamsObserver, public nsWrapperCache {
  private:
   ~URL() = default;
 
+  static already_AddRefed<nsIURI> ParseURI(const nsACString& aURL,
+                                           const Optional<nsACString>& aBase);
+
   void UpdateURLSearchParams();
 
  private:
-  void SetSearchInternal(const nsAString& aSearch);
+  void SetSearchInternal(const nsACString& aSearch);
 
   void CreateSearchParamsIfNeeded();
 
diff --git a/dom/url/URLMainThread.cpp b/dom/url/URLMainThread.cpp
index 95afd0db45..fb57be4401 100644
--- a/dom/url/URLMainThread.cpp
+++ b/dom/url/URLMainThread.cpp
@@ -19,7 +19,7 @@ namespace mozilla::dom {
 
 /* static */
 void URLMainThread::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                                    nsAString& aResult, ErrorResult& aRv) {
+                                    nsACString& aResult, ErrorResult& aRv) {
   MOZ_ASSERT(NS_IsMainThread());
 
   nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
@@ -41,20 +41,18 @@ void URLMainThread::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
   nsCOMPtr<nsIPrincipal> principal =
       nsContentUtils::ObjectPrincipal(aGlobal.Get());
 
-  nsAutoCString url;
   aRv = BlobURLProtocolHandler::AddDataEntry(
-      aBlob.Impl(), principal, NS_ConvertUTF16toUTF8(partKey), url);
+      aBlob.Impl(), principal, NS_ConvertUTF16toUTF8(partKey), aResult);
   if (NS_WARN_IF(aRv.Failed())) {
     return;
   }
 
-  global->RegisterHostObjectURI(url);
-  CopyASCIItoUTF16(url, aResult);
+  global->RegisterHostObjectURI(aResult);
 }
 
 /* static */
 void URLMainThread::CreateObjectURL(const GlobalObject& aGlobal,
-                                    MediaSource& aSource, nsAString& aResult,
+                                    MediaSource& aSource, nsACString& aResult,
                                     ErrorResult& aRv) {
   MOZ_ASSERT(NS_IsMainThread());
 
@@ -77,25 +75,23 @@ void URLMainThread::CreateObjectURL(const GlobalObject& aGlobal,
   nsCOMPtr<nsIPrincipal> principal =
       nsContentUtils::ObjectPrincipal(aGlobal.Get());
 
-  nsAutoCString url;
   aRv = BlobURLProtocolHandler::AddDataEntry(
-      &aSource, principal, NS_ConvertUTF16toUTF8(partKey), url);
+      &aSource, principal, NS_ConvertUTF16toUTF8(partKey), aResult);
   if (NS_WARN_IF(aRv.Failed())) {
     return;
   }
 
   nsCOMPtr<nsIRunnable> revocation = NS_NewRunnableFunction(
-      "dom::URLMainThread::CreateObjectURL",
-      [url] { BlobURLProtocolHandler::RemoveDataEntry(url); });
+      "dom::URLMainThread::CreateObjectURL", [result = nsCString(aResult)] {
+        BlobURLProtocolHandler::RemoveDataEntry(result);
+      });
 
   nsContentUtils::RunInStableState(revocation.forget());
-
-  CopyASCIItoUTF16(url, aResult);
 }
 
 /* static */
 void URLMainThread::RevokeObjectURL(const GlobalObject& aGlobal,
-                                    const nsAString& aURL, ErrorResult& aRv) {
+                                    const nsACString& aURL, ErrorResult& aRv) {
   MOZ_ASSERT(NS_IsMainThread());
   nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports());
   if (!global) {
@@ -113,21 +109,18 @@ void URLMainThread::RevokeObjectURL(const GlobalObject& aGlobal,
     }
   }
 
-  NS_LossyConvertUTF16toASCII asciiurl(aURL);
-
   if (BlobURLProtocolHandler::RemoveDataEntry(
-          asciiurl, nsContentUtils::ObjectPrincipal(aGlobal.Get()),
+          aURL, nsContentUtils::ObjectPrincipal(aGlobal.Get()),
           NS_ConvertUTF16toUTF8(partKey))) {
-    global->UnregisterHostObjectURI(asciiurl);
+    global->UnregisterHostObjectURI(aURL);
   }
 }
 
 /* static */
 bool URLMainThread::IsValidObjectURL(const GlobalObject& aGlobal,
-                                     const nsAString& aURL, ErrorResult& aRv) {
+                                     const nsACString& aURL, ErrorResult& aRv) {
   MOZ_ASSERT(NS_IsMainThread());
-  NS_LossyConvertUTF16toASCII asciiurl(aURL);
-  return BlobURLProtocolHandler::HasDataEntry(asciiurl);
+  return BlobURLProtocolHandler::HasDataEntry(aURL);
 }
 
 }  // namespace mozilla::dom
diff --git a/dom/url/URLMainThread.h b/dom/url/URLMainThread.h
index 5314f2b3e0..1d419aab78 100644
--- a/dom/url/URLMainThread.h
+++ b/dom/url/URLMainThread.h
@@ -14,16 +14,13 @@ namespace mozilla::dom {
 class URLMainThread final {
  public:
   static void CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                              nsAString& aResult, ErrorResult& aRv);
-
+                              nsACString& aResult, ErrorResult& aRv);
   static void CreateObjectURL(const GlobalObject& aGlobal, MediaSource& aSource,
-                              nsAString& aResult, ErrorResult& aRv);
-
+                              nsACString& aResult, ErrorResult& aRv);
   static void RevokeObjectURL(const GlobalObject& aGlobal,
-                              const nsAString& aURL, ErrorResult& aRv);
-
+                              const nsACString& aURL, ErrorResult& aRv);
   static bool IsValidObjectURL(const GlobalObject& aGlobal,
-                               const nsAString& aURL, ErrorResult& aRv);
+                               const nsACString& aURL, ErrorResult& aRv);
 };
 
 }  // namespace mozilla::dom
diff --git a/dom/url/URLSearchParams.cpp b/dom/url/URLSearchParams.cpp
index d43217c8b6..c141766e83 100644
--- a/dom/url/URLSearchParams.cpp
+++ b/dom/url/URLSearchParams.cpp
@@ -60,23 +60,24 @@ JSObject* URLSearchParams::WrapObject(JSContext* aCx,
 /* static */
 already_AddRefed<URLSearchParams> URLSearchParams::Constructor(
     const GlobalObject& aGlobal,
-    const USVStringSequenceSequenceOrUSVStringUSVStringRecordOrUSVString& aInit,
+    const UTF8StringSequenceSequenceOrUTF8StringUTF8StringRecordOrUTF8String&
+        aInit,
     ErrorResult& aRv) {
   RefPtr<URLSearchParams> sp =
       new URLSearchParams(aGlobal.GetAsSupports(), nullptr);
 
-  if (aInit.IsUSVString()) {
-    NS_ConvertUTF16toUTF8 input(aInit.GetAsUSVString());
+  if (aInit.IsUTF8String()) {
+    const auto& input = aInit.GetAsUTF8String();
     if (StringBeginsWith(input, "?"_ns)) {
       sp->ParseInput(Substring(input, 1, input.Length() - 1));
     } else {
       sp->ParseInput(input);
     }
-  } else if (aInit.IsUSVStringSequenceSequence()) {
-    const Sequence<Sequence<nsString>>& list =
-        aInit.GetAsUSVStringSequenceSequence();
+  } else if (aInit.IsUTF8StringSequenceSequence()) {
+    const Sequence<Sequence<nsCString>>& list =
+        aInit.GetAsUTF8StringSequenceSequence();
     for (uint32_t i = 0; i < list.Length(); ++i) {
-      const Sequence<nsString>& item = list[i];
+      const Sequence<nsCString>& item = list[i];
       if (item.Length() != 2) {
         nsPrintfCString err("Expected 2 items in pair but got %zu",
                             item.Length());
@@ -85,9 +86,9 @@ already_AddRefed<URLSearchParams> URLSearchParams::Constructor(
       }
       sp->Append(item[0], item[1]);
     }
-  } else if (aInit.IsUSVStringUSVStringRecord()) {
-    const Record<nsString, nsString>& record =
-        aInit.GetAsUSVStringUSVStringRecord();
+  } else if (aInit.IsUTF8StringUTF8StringRecord()) {
+    const Record<nsCString, nsCString>& record =
+        aInit.GetAsUTF8StringUTF8StringRecord();
     for (auto& entry : record.Entries()) {
       sp->Append(entry.mKey, entry.mValue);
     }
@@ -104,35 +105,36 @@ void URLSearchParams::ParseInput(const nsACString& aInput) {
 
 uint32_t URLSearchParams::Size() const { return mParams->Length(); }
 
-void URLSearchParams::Get(const nsAString& aName, nsString& aRetval) {
+void URLSearchParams::Get(const nsACString& aName, nsACString& aRetval) {
   return mParams->Get(aName, aRetval);
 }
 
-void URLSearchParams::GetAll(const nsAString& aName,
-                             nsTArray<nsString>& aRetval) {
+void URLSearchParams::GetAll(const nsACString& aName,
+                             nsTArray<nsCString>& aRetval) {
   return mParams->GetAll(aName, aRetval);
 }
 
-void URLSearchParams::Set(const nsAString& aName, const nsAString& aValue) {
+void URLSearchParams::Set(const nsACString& aName, const nsACString& aValue) {
   mParams->Set(aName, aValue);
   NotifyObserver();
 }
 
-void URLSearchParams::Append(const nsAString& aName, const nsAString& aValue) {
+void URLSearchParams::Append(const nsACString& aName,
+                             const nsACString& aValue) {
   mParams->Append(aName, aValue);
   NotifyObserver();
 }
 
-bool URLSearchParams::Has(const nsAString& aName,
-                          const Optional<nsAString>& aValue) {
+bool URLSearchParams::Has(const nsACString& aName,
+                          const Optional<nsACString>& aValue) {
   if (!aValue.WasPassed()) {
     return mParams->Has(aName);
   }
   return mParams->Has(aName, aValue.Value());
 }
 
-void URLSearchParams::Delete(const nsAString& aName,
-                             const Optional<nsAString>& aValue) {
+void URLSearchParams::Delete(const nsACString& aName,
+                             const Optional<nsACString>& aValue) {
   if (!aValue.WasPassed()) {
     mParams->Delete(aName);
     NotifyObserver();
@@ -144,10 +146,17 @@ void URLSearchParams::Delete(const nsAString& aName,
 
 void URLSearchParams::DeleteAll() { mParams->DeleteAll(); }
 
-void URLSearchParams::Serialize(nsAString& aValue) const {
+void URLSearchParams::Serialize(nsACString& aValue) const {
   mParams->Serialize(aValue, true);
 }
 
+// TODO(emilio): Allow stringifier attributes with CString return values.
+void URLSearchParams::Stringify(nsAString& aValue) const {
+  nsAutoCString serialized;
+  mParams->Serialize(serialized, true);
+  CopyUTF8toUTF16(serialized, aValue);
+}
+
 void URLSearchParams::NotifyObserver() {
   if (mObserver) {
     mObserver->URLSearchParamsUpdated(this);
@@ -158,11 +167,11 @@ uint32_t URLSearchParams::GetIterableLength() const {
   return mParams->Length();
 }
 
-const nsAString& URLSearchParams::GetKeyAtIndex(uint32_t aIndex) const {
+const nsACString& URLSearchParams::GetKeyAtIndex(uint32_t aIndex) const {
   return mParams->GetKeyAtIndex(aIndex);
 }
 
-const nsAString& URLSearchParams::GetValueAtIndex(uint32_t aIndex) const {
+const nsACString& URLSearchParams::GetValueAtIndex(uint32_t aIndex) const {
   return mParams->GetValueAtIndex(aIndex);
 }
 
@@ -182,11 +191,10 @@ nsresult URLSearchParams::GetSendInfo(nsIInputStream** aBody,
       "application/x-www-form-urlencoded;charset=UTF-8");
   aCharset.AssignLiteral("UTF-8");
 
-  nsAutoString serialized;
+  nsAutoCString serialized;
   Serialize(serialized);
-  NS_ConvertUTF16toUTF8 converted(serialized);
-  *aContentLength = converted.Length();
-  return NS_NewCStringInputStream(aBody, std::move(converted));
+  *aContentLength = serialized.Length();
+  return NS_NewCStringInputStream(aBody, std::move(serialized));
 }
 
 }  // namespace mozilla::dom
diff --git a/dom/url/URLSearchParams.h b/dom/url/URLSearchParams.h
index 9ddff1e512..25bd293f4d 100644
--- a/dom/url/URLSearchParams.h
+++ b/dom/url/URLSearchParams.h
@@ -37,7 +37,7 @@ namespace dom {
 
 class GlobalObject;
 class URLSearchParams;
-class USVStringSequenceSequenceOrUSVStringUSVStringRecordOrUSVString;
+class UTF8StringSequenceSequenceOrUTF8StringUTF8StringRecordOrUTF8String;
 template <typename T>
 class Optional;
 
@@ -66,42 +66,42 @@ class URLSearchParams final : public nsISupports, public nsWrapperCache {
 
   static already_AddRefed<URLSearchParams> Constructor(
       const GlobalObject& aGlobal,
-      const USVStringSequenceSequenceOrUSVStringUSVStringRecordOrUSVString&
+      const UTF8StringSequenceSequenceOrUTF8StringUTF8StringRecordOrUTF8String&
           aInit,
       ErrorResult& aRv);
 
   void ParseInput(const nsACString& aInput);
 
-  void Serialize(nsAString& aValue) const;
+  void Serialize(nsACString& aValue) const;
 
   uint32_t Size() const;
 
-  void Get(const nsAString& aName, nsString& aRetval);
+  void Get(const nsACString& aName, nsACString& aRetval);
 
-  void GetAll(const nsAString& aName, nsTArray<nsString>& aRetval);
+  void GetAll(const nsACString& aName, nsTArray<nsCString>& aRetval);
 
-  void Set(const nsAString& aName, const nsAString& aValue);
+  void Set(const nsACString& aName, const nsACString& aValue);
 
-  void Append(const nsAString& aName, const nsAString& aValue);
+  void Append(const nsACString& aName, const nsACString& aValue);
 
-  bool Has(const nsAString& aName, const Optional<nsAString>& aValue);
+  bool Has(const nsACString& aName, const Optional<nsACString>& aValue);
 
-  void Delete(const nsAString& aName, const Optional<nsAString>& aValue);
+  void Delete(const nsACString& aName, const Optional<nsACString>& aValue);
 
   uint32_t GetIterableLength() const;
-  const nsAString& GetKeyAtIndex(uint32_t aIndex) const;
-  const nsAString& GetValueAtIndex(uint32_t aIndex) const;
+  const nsACString& GetKeyAtIndex(uint32_t aIndex) const;
+  const nsACString& GetValueAtIndex(uint32_t aIndex) const;
 
   void Sort(ErrorResult& aRv);
 
-  void Stringify(nsString& aRetval) const { Serialize(aRetval); }
+  void Stringify(nsAString&) const;
 
   nsresult GetSendInfo(nsIInputStream** aBody, uint64_t* aContentLength,
                        nsACString& aContentTypeWithCharset,
                        nsACString& aCharset) const;
 
  private:
-  void AppendInternal(const nsAString& aName, const nsAString& aValue);
+  void AppendInternal(const nsACString& aName, const nsACString& aValue);
 
   void DeleteAll();
 
diff --git a/dom/url/URLWorker.cpp b/dom/url/URLWorker.cpp
index e4ae3d6248..cb902b8cd3 100644
--- a/dom/url/URLWorker.cpp
+++ b/dom/url/URLWorker.cpp
@@ -18,11 +18,11 @@ namespace mozilla::dom {
 class CreateURLRunnable : public WorkerMainThreadRunnable {
  private:
   BlobImpl* mBlobImpl;
-  nsAString& mURL;
+  nsACString& mURL;
 
  public:
   CreateURLRunnable(WorkerPrivate* aWorkerPrivate, BlobImpl* aBlobImpl,
-                    nsAString& aURL)
+                    nsACString& aURL)
       : WorkerMainThreadRunnable(aWorkerPrivate, "URL :: CreateURL"_ns),
         mBlobImpl(aBlobImpl),
         mURL(aURL) {
@@ -42,17 +42,13 @@ class CreateURLRunnable : public WorkerMainThreadRunnable {
     nsAutoString partKey;
     cookieJarSettings->GetPartitionKey(partKey);
 
-    nsAutoCString url;
     nsresult rv = BlobURLProtocolHandler::AddDataEntry(
-        mBlobImpl, principal, NS_ConvertUTF16toUTF8(partKey), url);
-
+        mBlobImpl, principal, NS_ConvertUTF16toUTF8(partKey), mURL);
     if (NS_FAILED(rv)) {
       NS_WARNING("Failed to add data entry for the blob!");
-      SetDOMStringToNull(mURL);
+      mURL.SetIsVoid(true);
       return false;
     }
-
-    CopyUTF8toUTF16(url, mURL);
     return true;
   }
 };
@@ -60,26 +56,24 @@ class CreateURLRunnable : public WorkerMainThreadRunnable {
 // This class revokes an URL on the main thread.
 class RevokeURLRunnable : public WorkerMainThreadRunnable {
  private:
-  const nsString mURL;
+  const nsCString mURL;
 
  public:
-  RevokeURLRunnable(WorkerPrivate* aWorkerPrivate, const nsAString& aURL)
+  RevokeURLRunnable(WorkerPrivate* aWorkerPrivate, const nsACString& aURL)
       : WorkerMainThreadRunnable(aWorkerPrivate, "URL :: RevokeURL"_ns),
         mURL(aURL) {}
 
   bool MainThreadRun() override {
     AssertIsOnMainThread();
 
-    NS_ConvertUTF16toUTF8 url(mURL);
-
     nsCOMPtr<nsICookieJarSettings> cookieJarSettings =
         mWorkerPrivate->CookieJarSettings();
 
     nsAutoString partKey;
     cookieJarSettings->GetPartitionKey(partKey);
 
-    BlobURLProtocolHandler::RemoveDataEntry(url, mWorkerPrivate->GetPrincipal(),
-                                            NS_ConvertUTF16toUTF8(partKey));
+    BlobURLProtocolHandler::RemoveDataEntry(
+        mURL, mWorkerPrivate->GetPrincipal(), NS_ConvertUTF16toUTF8(partKey));
     return true;
   }
 };
@@ -87,11 +81,11 @@ class RevokeURLRunnable : public WorkerMainThreadRunnable {
 // This class checks if an URL is valid on the main thread.
 class IsValidURLRunnable : public WorkerMainThreadRunnable {
  private:
-  const nsString mURL;
+  const nsCString mURL;
   bool mValid;
 
  public:
-  IsValidURLRunnable(WorkerPrivate* aWorkerPrivate, const nsAString& aURL)
+  IsValidURLRunnable(WorkerPrivate* aWorkerPrivate, const nsACString& aURL)
       : WorkerMainThreadRunnable(aWorkerPrivate, "URL :: IsValidURL"_ns),
         mURL(aURL),
         mValid(false) {}
@@ -99,8 +93,7 @@ class IsValidURLRunnable : public WorkerMainThreadRunnable {
   bool MainThreadRun() override {
     AssertIsOnMainThread();
 
-    NS_ConvertUTF16toUTF8 url(mURL);
-    mValid = BlobURLProtocolHandler::HasDataEntry(url);
+    mValid = BlobURLProtocolHandler::HasDataEntry(mURL);
 
     return true;
   }
@@ -110,7 +103,8 @@ class IsValidURLRunnable : public WorkerMainThreadRunnable {
 
 /* static */
 void URLWorker::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                                nsAString& aResult, mozilla::ErrorResult& aRv) {
+                                nsACString& aResult,
+                                mozilla::ErrorResult& aRv) {
   JSContext* cx = aGlobal.Context();
   WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(cx);
 
@@ -128,12 +122,12 @@ void URLWorker::CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
   WorkerGlobalScope* scope = workerPrivate->GlobalScope();
   MOZ_ASSERT(scope);
 
-  scope->RegisterHostObjectURI(NS_ConvertUTF16toUTF8(aResult));
+  scope->RegisterHostObjectURI(aResult);
 }
 
 /* static */
 void URLWorker::RevokeObjectURL(const GlobalObject& aGlobal,
-                                const nsAString& aUrl, ErrorResult& aRv) {
+                                const nsACString& aUrl, ErrorResult& aRv) {
   JSContext* cx = aGlobal.Context();
   WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(cx);
 
@@ -148,12 +142,12 @@ void URLWorker::RevokeObjectURL(const GlobalObject& aGlobal,
   WorkerGlobalScope* scope = workerPrivate->GlobalScope();
   MOZ_ASSERT(scope);
 
-  scope->UnregisterHostObjectURI(NS_ConvertUTF16toUTF8(aUrl));
+  scope->UnregisterHostObjectURI(aUrl);
 }
 
 /* static */
 bool URLWorker::IsValidObjectURL(const GlobalObject& aGlobal,
-                                 const nsAString& aUrl, ErrorResult& aRv) {
+                                 const nsACString& aUrl, ErrorResult& aRv) {
   JSContext* cx = aGlobal.Context();
   WorkerPrivate* workerPrivate = GetWorkerPrivateFromContext(cx);
 
diff --git a/dom/url/URLWorker.h b/dom/url/URLWorker.h
index be8ab512a1..8424e35cca 100644
--- a/dom/url/URLWorker.h
+++ b/dom/url/URLWorker.h
@@ -21,22 +21,20 @@ namespace dom {
 class URLWorker final {
  public:
   static already_AddRefed<URLWorker> Constructor(
-      const GlobalObject& aGlobal, const nsAString& aURL,
-      const Optional<nsAString>& aBase, ErrorResult& aRv);
+      const GlobalObject& aGlobal, const nsACString& aURL,
+      const Optional<nsACString>& aBase, ErrorResult& aRv);
 
   static already_AddRefed<URLWorker> Constructor(const GlobalObject& aGlobal,
-                                                 const nsAString& aURL,
-                                                 const nsAString& aBase,
+                                                 const nsACString& aURL,
+                                                 const nsACString& aBase,
                                                  ErrorResult& aRv);
 
   static void CreateObjectURL(const GlobalObject& aGlobal, Blob& aBlob,
-                              nsAString& aResult, mozilla::ErrorResult& aRv);
-
+                              nsACString& aResult, mozilla::ErrorResult& aRv);
   static void RevokeObjectURL(const GlobalObject& aGlobal,
-                              const nsAString& aUrl, ErrorResult& aRv);
-
+                              const nsACString& aUrl, ErrorResult& aRv);
   static bool IsValidObjectURL(const GlobalObject& aGlobal,
-                               const nsAString& aUrl, ErrorResult& aRv);
+                               const nsACString& aUrl, ErrorResult& aRv);
 };
 
 }  // namespace dom