Adding upstream version 115.8.0esr.upstream/115.8.0esr

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

1 files changed, 680 insertions, 0 deletions

diff --git a/chrome/nsChromeRegistryChrome.cpp b/chrome/nsChromeRegistryChrome.cpp
new file mode 100644
index 0000000000..0bb93b4cfa
--- /dev/null
+++ b/chrome/nsChromeRegistryChrome.cpp
@@ -0,0 +1,680 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 sts=2 sw=2 et tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/dom/ContentParent.h"
+#include "RegistryMessageUtils.h"
+#include "nsResProtocolHandler.h"
+
+#include "nsChromeRegistryChrome.h"
+
+#if defined(XP_WIN)
+#  include <windows.h>
+#elif defined(XP_MACOSX)
+#  include <CoreServices/CoreServices.h>
+#endif
+
+#include "nsArrayEnumerator.h"
+#include "nsComponentManager.h"
+#include "nsEnumeratorUtils.h"
+#include "nsNetUtil.h"
+#include "nsStringEnumerator.h"
+#include "nsTextFormatter.h"
+#include "nsXPCOMCIDInternal.h"
+
+#include "mozilla/LookAndFeel.h"
+#include "mozilla/Unused.h"
+
+#include "nsIObserverService.h"
+#include "mozilla/AppShutdown.h"
+#include "mozilla/Components.h"
+#include "mozilla/Preferences.h"
+#include "nsIResProtocolHandler.h"
+#include "nsIScriptError.h"
+#include "nsIXULRuntime.h"
+
+#define PACKAGE_OVERRIDE_BRANCH "chrome.override_package."
+#define SKIN "classic/1.0"_ns
+
+using namespace mozilla;
+using mozilla::dom::ContentParent;
+using mozilla::dom::PContentParent;
+using mozilla::intl::LocaleService;
+
+// We use a "best-fit" algorithm for matching locales and themes.
+// 1) the exact selected locale/theme
+// 2) (locales only) same language, different country
+//    e.g. en-GB is the selected locale, only en-US is available
+// 3) any available locale/theme
+
+/**
+ * Match the language-part of two lang-COUNTRY codes, hopefully but
+ * not guaranteed to be in the form ab-CD or abz-CD. "ab" should also
+ * work, any other garbage-in will produce undefined results as long
+ * as it does not crash.
+ */
+static bool LanguagesMatch(const nsACString& a, const nsACString& b) {
+  if (a.Length() < 2 || b.Length() < 2) return false;
+
+  nsACString::const_iterator as, ae, bs, be;
+  a.BeginReading(as);
+  a.EndReading(ae);
+  b.BeginReading(bs);
+  b.EndReading(be);
+
+  while (*as == *bs) {
+    if (*as == '-') return true;
+
+    ++as;
+    ++bs;
+
+    // reached the end
+    if (as == ae && bs == be) return true;
+
+    // "a" is short
+    if (as == ae) return (*bs == '-');
+
+    // "b" is short
+    if (bs == be) return (*as == '-');
+  }
+
+  return false;
+}
+
+nsChromeRegistryChrome::nsChromeRegistryChrome()
+    : mProfileLoaded(false), mDynamicRegistration(true) {}
+
+nsChromeRegistryChrome::~nsChromeRegistryChrome() {}
+
+nsresult nsChromeRegistryChrome::Init() {
+  nsresult rv = nsChromeRegistry::Init();
+  if (NS_FAILED(rv)) return rv;
+
+  bool safeMode = false;
+  nsCOMPtr<nsIXULRuntime> xulrun(do_GetService(XULAPPINFO_SERVICE_CONTRACTID));
+  if (xulrun) xulrun->GetInSafeMode(&safeMode);
+
+  nsCOMPtr<nsIObserverService> obsService =
+      mozilla::services::GetObserverService();
+  if (obsService) {
+    obsService->AddObserver(this, "profile-initial-state", true);
+    obsService->AddObserver(this, "intl:app-locales-changed", true);
+  }
+
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsChromeRegistryChrome::GetLocalesForPackage(
+    const nsACString& aPackage, nsIUTF8StringEnumerator** aResult) {
+  nsCString realpackage;
+  nsresult rv = OverrideLocalePackage(aPackage, realpackage);
+  if (NS_FAILED(rv)) return rv;
+
+  nsTArray<nsCString>* a = new nsTArray<nsCString>;
+  if (!a) return NS_ERROR_OUT_OF_MEMORY;
+
+  PackageEntry* entry;
+  if (mPackagesHash.Get(realpackage, &entry)) {
+    entry->locales.EnumerateToArray(a);
+  }
+
+  rv = NS_NewAdoptingUTF8StringEnumerator(aResult, a);
+  if (NS_FAILED(rv)) delete a;
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsChromeRegistryChrome::IsLocaleRTL(const nsACString& package, bool* aResult) {
+  *aResult = false;
+
+  nsAutoCString locale;
+  GetSelectedLocale(package, locale);
+  if (locale.Length() < 2) return NS_OK;
+
+  *aResult = LocaleService::IsLocaleRTL(locale);
+  return NS_OK;
+}
+
+/**
+ * This method negotiates only between the app locale and the available
+ * chrome packages.
+ *
+ * If you want to get the current application's UI locale, please use
+ * LocaleService::GetAppLocaleAsBCP47.
+ */
+nsresult nsChromeRegistryChrome::GetSelectedLocale(const nsACString& aPackage,
+                                                   nsACString& aLocale) {
+  nsAutoCString reqLocale;
+  if (aPackage.EqualsLiteral("global")) {
+    LocaleService::GetInstance()->GetAppLocaleAsBCP47(reqLocale);
+  } else {
+    AutoTArray<nsCString, 10> requestedLocales;
+    LocaleService::GetInstance()->GetRequestedLocales(requestedLocales);
+    reqLocale.Assign(requestedLocales[0]);
+  }
+
+  nsCString realpackage;
+  nsresult rv = OverrideLocalePackage(aPackage, realpackage);
+  if (NS_FAILED(rv)) return rv;
+  PackageEntry* entry;
+  if (!mPackagesHash.Get(realpackage, &entry)) return NS_ERROR_FILE_NOT_FOUND;
+
+  aLocale = entry->locales.GetSelected(reqLocale, nsProviderArray::LOCALE);
+  if (aLocale.IsEmpty()) return NS_ERROR_FAILURE;
+
+  return NS_OK;
+}
+
+nsresult nsChromeRegistryChrome::OverrideLocalePackage(
+    const nsACString& aPackage, nsACString& aOverride) {
+  const nsACString& pref = nsLiteralCString(PACKAGE_OVERRIDE_BRANCH) + aPackage;
+  nsAutoCString override;
+  nsresult rv = mozilla::Preferences::GetCString(PromiseFlatCString(pref).get(),
+                                                 override);
+  if (NS_SUCCEEDED(rv)) {
+    aOverride = override;
+  } else {
+    aOverride = aPackage;
+  }
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+nsChromeRegistryChrome::Observe(nsISupports* aSubject, const char* aTopic,
+                                const char16_t* someData) {
+  nsresult rv = NS_OK;
+
+  if (!strcmp("profile-initial-state", aTopic)) {
+    mProfileLoaded = true;
+  } else if (!strcmp("intl:app-locales-changed", aTopic)) {
+    if (mProfileLoaded) {
+      FlushAllCaches();
+    }
+  } else {
+    NS_ERROR("Unexpected observer topic!");
+  }
+
+  return rv;
+}
+
+NS_IMETHODIMP
+nsChromeRegistryChrome::CheckForNewChrome() {
+  if (AppShutdown::IsInOrBeyond(ShutdownPhase::AppShutdownConfirmed)) {
+    MOZ_ASSERT(false, "checking for new chrome during shutdown");
+    return NS_ERROR_UNEXPECTED;
+  }
+
+  mPackagesHash.Clear();
+  mOverrideTable.Clear();
+
+  mDynamicRegistration = false;
+
+  nsComponentManagerImpl::gComponentManager->RereadChromeManifests();
+
+  mDynamicRegistration = true;
+
+  SendRegisteredChrome(nullptr);
+  return NS_OK;
+}
+
+static void SerializeURI(nsIURI* aURI, SerializedURI& aSerializedURI) {
+  if (!aURI) return;
+
+  aURI->GetSpec(aSerializedURI.spec);
+}
+
+void nsChromeRegistryChrome::SendRegisteredChrome(
+    mozilla::dom::PContentParent* aParent) {
+  nsTArray<ChromePackage> packages;
+  nsTArray<SubstitutionMapping> resources;
+  nsTArray<OverrideMapping> overrides;
+
+  for (const auto& entry : mPackagesHash) {
+    ChromePackage chromePackage;
+    ChromePackageFromPackageEntry(entry.GetKey(), entry.GetWeak(),
+                                  &chromePackage, SKIN);
+    packages.AppendElement(chromePackage);
+  }
+
+  // If we were passed a parent then a new child process has been created and
+  // has requested all of the chrome so send it the resources too. Otherwise
+  // resource mappings are sent by the resource protocol handler dynamically.
+  if (aParent) {
+    nsCOMPtr<nsIIOService> io(do_GetIOService());
+    NS_ENSURE_TRUE_VOID(io);
+
+    nsCOMPtr<nsIProtocolHandler> ph;
+    nsresult rv = io->GetProtocolHandler("resource", getter_AddRefs(ph));
+    NS_ENSURE_SUCCESS_VOID(rv);
+
+    nsCOMPtr<nsIResProtocolHandler> irph(do_QueryInterface(ph));
+    nsResProtocolHandler* rph = static_cast<nsResProtocolHandler*>(irph.get());
+    rv = rph->CollectSubstitutions(resources);
+    NS_ENSURE_SUCCESS_VOID(rv);
+  }
+
+  for (const auto& entry : mOverrideTable) {
+    SerializedURI chromeURI, overrideURI;
+
+    SerializeURI(entry.GetKey(), chromeURI);
+    SerializeURI(entry.GetWeak(), overrideURI);
+
+    overrides.AppendElement(
+        OverrideMapping{std::move(chromeURI), std::move(overrideURI)});
+  }
+
+  nsAutoCString appLocale;
+  LocaleService::GetInstance()->GetAppLocaleAsBCP47(appLocale);
+
+  if (aParent) {
+    bool success = aParent->SendRegisterChrome(packages, resources, overrides,
+                                               appLocale, false);
+    NS_ENSURE_TRUE_VOID(success);
+  } else {
+    nsTArray<ContentParent*> parents;
+    ContentParent::GetAll(parents);
+    if (!parents.Length()) return;
+
+    for (uint32_t i = 0; i < parents.Length(); i++) {
+      DebugOnly<bool> success = parents[i]->SendRegisterChrome(
+          packages, resources, overrides, appLocale, true);
+      NS_WARNING_ASSERTION(success,
+                           "couldn't reset a child's registered chrome");
+    }
+  }
+}
+
+/* static */
+void nsChromeRegistryChrome::ChromePackageFromPackageEntry(
+    const nsACString& aPackageName, PackageEntry* aPackage,
+    ChromePackage* aChromePackage, const nsCString& aSelectedSkin) {
+  nsAutoCString appLocale;
+  LocaleService::GetInstance()->GetAppLocaleAsBCP47(appLocale);
+
+  SerializeURI(aPackage->baseURI, aChromePackage->contentBaseURI);
+  SerializeURI(aPackage->locales.GetBase(appLocale, nsProviderArray::LOCALE),
+               aChromePackage->localeBaseURI);
+  SerializeURI(aPackage->skins.GetBase(aSelectedSkin, nsProviderArray::ANY),
+               aChromePackage->skinBaseURI);
+  aChromePackage->package = aPackageName;
+  aChromePackage->flags = aPackage->flags;
+}
+
+static bool CanLoadResource(nsIURI* aResourceURI) {
+  bool isLocalResource = false;
+  (void)NS_URIChainHasFlags(aResourceURI,
+                            nsIProtocolHandler::URI_IS_LOCAL_RESOURCE,
+                            &isLocalResource);
+  return isLocalResource;
+}
+
+nsIURI* nsChromeRegistryChrome::GetBaseURIFromPackage(
+    const nsCString& aPackage, const nsCString& aProvider,
+    const nsCString& aPath) {
+  PackageEntry* entry;
+  if (!mPackagesHash.Get(aPackage, &entry)) {
+    if (!mInitialized) return nullptr;
+
+    LogMessage("No chrome package registered for chrome://%s/%s/%s",
+               aPackage.get(), aProvider.get(), aPath.get());
+
+    return nullptr;
+  }
+
+  if (aProvider.EqualsLiteral("locale")) {
+    nsAutoCString appLocale;
+    LocaleService::GetInstance()->GetAppLocaleAsLangTag(appLocale);
+    return entry->locales.GetBase(appLocale, nsProviderArray::LOCALE);
+  }
+
+  if (aProvider.EqualsLiteral("skin")) {
+    return entry->skins.GetBase(SKIN, nsProviderArray::ANY);
+  }
+
+  if (aProvider.EqualsLiteral("content")) {
+    return entry->baseURI;
+  }
+  return nullptr;
+}
+
+nsresult nsChromeRegistryChrome::GetFlagsFromPackage(const nsCString& aPackage,
+                                                     uint32_t* aFlags) {
+  PackageEntry* entry;
+  if (!mPackagesHash.Get(aPackage, &entry)) return NS_ERROR_FILE_NOT_FOUND;
+
+  *aFlags = entry->flags;
+  return NS_OK;
+}
+
+nsChromeRegistryChrome::ProviderEntry*
+nsChromeRegistryChrome::nsProviderArray::GetProvider(
+    const nsACString& aPreferred, MatchType aType) {
+  size_t i = mArray.Length();
+  if (!i) return nullptr;
+
+  ProviderEntry* found = nullptr;  // Only set if we find a partial-match locale
+  ProviderEntry* entry = nullptr;
+
+  while (i--) {
+    entry = &mArray[i];
+    if (aPreferred.Equals(entry->provider)) return entry;
+
+    if (aType != LOCALE) continue;
+
+    if (LanguagesMatch(aPreferred, entry->provider)) {
+      found = entry;
+      continue;
+    }
+
+    if (!found && entry->provider.EqualsLiteral("en-US")) found = entry;
+  }
+
+  if (!found && aType != EXACT) return entry;
+
+  return found;
+}
+
+nsIURI* nsChromeRegistryChrome::nsProviderArray::GetBase(
+    const nsACString& aPreferred, MatchType aType) {
+  ProviderEntry* provider = GetProvider(aPreferred, aType);
+
+  if (!provider) return nullptr;
+
+  return provider->baseURI;
+}
+
+const nsACString& nsChromeRegistryChrome::nsProviderArray::GetSelected(
+    const nsACString& aPreferred, MatchType aType) {
+  ProviderEntry* entry = GetProvider(aPreferred, aType);
+
+  if (entry) return entry->provider;
+
+  return EmptyCString();
+}
+
+void nsChromeRegistryChrome::nsProviderArray::SetBase(
+    const nsACString& aProvider, nsIURI* aBaseURL) {
+  ProviderEntry* provider = GetProvider(aProvider, EXACT);
+
+  if (provider) {
+    provider->baseURI = aBaseURL;
+    return;
+  }
+
+  // no existing entries, add a new one
+  mArray.AppendElement(ProviderEntry(aProvider, aBaseURL));
+}
+
+void nsChromeRegistryChrome::nsProviderArray::EnumerateToArray(
+    nsTArray<nsCString>* a) {
+  int32_t i = mArray.Length();
+  while (i--) {
+    a->AppendElement(mArray[i].provider);
+  }
+}
+
+nsIURI* nsChromeRegistry::ManifestProcessingContext::GetManifestURI() {
+  if (!mManifestURI) {
+    nsCString uri;
+    mFile.GetURIString(uri);
+    NS_NewURI(getter_AddRefs(mManifestURI), uri);
+  }
+  return mManifestURI;
+}
+
+already_AddRefed<nsIURI>
+nsChromeRegistry::ManifestProcessingContext::ResolveURI(const char* uri) {
+  nsIURI* baseuri = GetManifestURI();
+  if (!baseuri) return nullptr;
+
+  nsCOMPtr<nsIURI> resolved;
+  nsresult rv = NS_NewURI(getter_AddRefs(resolved), uri, baseuri);
+  if (NS_FAILED(rv)) return nullptr;
+
+  return resolved.forget();
+}
+
+static void EnsureLowerCase(char* aBuf) {
+  for (; *aBuf; ++aBuf) {
+    char ch = *aBuf;
+    if (ch >= 'A' && ch <= 'Z') *aBuf = ch + 'a' - 'A';
+  }
+}
+
+static void SendManifestEntry(const ChromeRegistryItem& aItem) {
+  nsTArray<ContentParent*> parents;
+  ContentParent::GetAll(parents);
+  if (!parents.Length()) return;
+
+  for (uint32_t i = 0; i < parents.Length(); i++) {
+    Unused << parents[i]->SendRegisterChromeItem(aItem);
+  }
+}
+
+void nsChromeRegistryChrome::ManifestContent(ManifestProcessingContext& cx,
+                                             int lineno, char* const* argv,
+                                             int flags) {
+  char* package = argv[0];
+  char* uri = argv[1];
+
+  EnsureLowerCase(package);
+
+  nsCOMPtr<nsIURI> resolved = cx.ResolveURI(uri);
+  if (!resolved) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "During chrome registration, unable to create URI '%s'.", uri);
+    return;
+  }
+
+  if (!CanLoadResource(resolved)) {
+    LogMessageWithContext(resolved, lineno, nsIScriptError::warningFlag,
+                          "During chrome registration, cannot register "
+                          "non-local URI '%s' as content.",
+                          uri);
+    return;
+  }
+
+  nsDependentCString packageName(package);
+  PackageEntry* entry = mPackagesHash.GetOrInsertNew(packageName);
+  entry->baseURI = resolved;
+  entry->flags = flags;
+
+  if (mDynamicRegistration) {
+    ChromePackage chromePackage;
+    ChromePackageFromPackageEntry(packageName, entry, &chromePackage, SKIN);
+    SendManifestEntry(chromePackage);
+  }
+}
+
+void nsChromeRegistryChrome::ManifestLocale(ManifestProcessingContext& cx,
+                                            int lineno, char* const* argv,
+                                            int flags) {
+  char* package = argv[0];
+  char* provider = argv[1];
+  char* uri = argv[2];
+
+  EnsureLowerCase(package);
+
+  nsCOMPtr<nsIURI> resolved = cx.ResolveURI(uri);
+  if (!resolved) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "During chrome registration, unable to create URI '%s'.", uri);
+    return;
+  }
+
+  if (!CanLoadResource(resolved)) {
+    LogMessageWithContext(resolved, lineno, nsIScriptError::warningFlag,
+                          "During chrome registration, cannot register "
+                          "non-local URI '%s' as content.",
+                          uri);
+    return;
+  }
+
+  nsDependentCString packageName(package);
+  PackageEntry* entry = mPackagesHash.GetOrInsertNew(packageName);
+  entry->locales.SetBase(nsDependentCString(provider), resolved);
+
+  if (mDynamicRegistration) {
+    ChromePackage chromePackage;
+    ChromePackageFromPackageEntry(packageName, entry, &chromePackage, SKIN);
+    SendManifestEntry(chromePackage);
+  }
+
+  // We use mainPackage as the package we track for reporting new locales being
+  // registered. For most cases it will be "global", but for Fennec it will be
+  // "browser".
+  nsAutoCString mainPackage;
+  nsresult rv = OverrideLocalePackage("global"_ns, mainPackage);
+  if (NS_FAILED(rv)) {
+    return;
+  }
+}
+
+void nsChromeRegistryChrome::ManifestSkin(ManifestProcessingContext& cx,
+                                          int lineno, char* const* argv,
+                                          int flags) {
+  char* package = argv[0];
+  char* provider = argv[1];
+  char* uri = argv[2];
+
+  EnsureLowerCase(package);
+
+  nsCOMPtr<nsIURI> resolved = cx.ResolveURI(uri);
+  if (!resolved) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "During chrome registration, unable to create URI '%s'.", uri);
+    return;
+  }
+
+  if (!CanLoadResource(resolved)) {
+    LogMessageWithContext(resolved, lineno, nsIScriptError::warningFlag,
+                          "During chrome registration, cannot register "
+                          "non-local URI '%s' as content.",
+                          uri);
+    return;
+  }
+
+  nsDependentCString packageName(package);
+  PackageEntry* entry = mPackagesHash.GetOrInsertNew(packageName);
+  entry->skins.SetBase(nsDependentCString(provider), resolved);
+
+  if (mDynamicRegistration) {
+    ChromePackage chromePackage;
+    ChromePackageFromPackageEntry(packageName, entry, &chromePackage, SKIN);
+    SendManifestEntry(chromePackage);
+  }
+}
+
+void nsChromeRegistryChrome::ManifestOverride(ManifestProcessingContext& cx,
+                                              int lineno, char* const* argv,
+                                              int flags) {
+  char* chrome = argv[0];
+  char* resolved = argv[1];
+
+  nsCOMPtr<nsIURI> chromeuri = cx.ResolveURI(chrome);
+  nsCOMPtr<nsIURI> resolveduri = cx.ResolveURI(resolved);
+  if (!chromeuri || !resolveduri) {
+    LogMessageWithContext(cx.GetManifestURI(), lineno,
+                          nsIScriptError::warningFlag,
+                          "During chrome registration, unable to create URI.");
+    return;
+  }
+
+  if (cx.mType == NS_SKIN_LOCATION) {
+    bool chromeSkinOnly =
+        chromeuri->SchemeIs("chrome") && resolveduri->SchemeIs("chrome");
+    if (chromeSkinOnly) {
+      nsAutoCString chromePath, resolvedPath;
+      chromeuri->GetPathQueryRef(chromePath);
+      resolveduri->GetPathQueryRef(resolvedPath);
+      chromeSkinOnly = StringBeginsWith(chromePath, "/skin/"_ns) &&
+                       StringBeginsWith(resolvedPath, "/skin/"_ns);
+    }
+    if (!chromeSkinOnly) {
+      LogMessageWithContext(
+          cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+          "Cannot register non-chrome://.../skin/ URIs '%s' and '%s' as "
+          "overrides and/or to be overridden from a skin manifest.",
+          chrome, resolved);
+      return;
+    }
+  }
+
+  if (!CanLoadResource(resolveduri)) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "Cannot register non-local URI '%s' for an override.", resolved);
+    return;
+  }
+  mOverrideTable.InsertOrUpdate(chromeuri, resolveduri);
+
+  if (mDynamicRegistration) {
+    SerializedURI serializedChrome;
+    SerializedURI serializedOverride;
+
+    SerializeURI(chromeuri, serializedChrome);
+    SerializeURI(resolveduri, serializedOverride);
+
+    OverrideMapping override = {serializedChrome, serializedOverride};
+    SendManifestEntry(override);
+  }
+}
+
+void nsChromeRegistryChrome::ManifestResource(ManifestProcessingContext& cx,
+                                              int lineno, char* const* argv,
+                                              int flags) {
+  char* package = argv[0];
+  char* uri = argv[1];
+
+  EnsureLowerCase(package);
+  nsDependentCString host(package);
+
+  nsCOMPtr<nsIIOService> io = mozilla::components::IO::Service();
+  if (!io) {
+    NS_WARNING("No IO service trying to process chrome manifests");
+    return;
+  }
+
+  nsCOMPtr<nsIProtocolHandler> ph;
+  nsresult rv = io->GetProtocolHandler("resource", getter_AddRefs(ph));
+  if (NS_FAILED(rv)) return;
+
+  nsCOMPtr<nsIResProtocolHandler> rph = do_QueryInterface(ph);
+
+  nsCOMPtr<nsIURI> resolved = cx.ResolveURI(uri);
+  if (!resolved) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "During chrome registration, unable to create URI '%s'.", uri);
+    return;
+  }
+
+  if (!CanLoadResource(resolved)) {
+    LogMessageWithContext(
+        cx.GetManifestURI(), lineno, nsIScriptError::warningFlag,
+        "Warning: cannot register non-local URI '%s' as a resource.", uri);
+    return;
+  }
+
+  // By default, Firefox resources are not content-accessible unless the
+  // manifests opts in.
+  bool contentAccessible = (flags & nsChromeRegistry::CONTENT_ACCESSIBLE);
+
+  uint32_t substitutionFlags = 0;
+  if (contentAccessible) {
+    substitutionFlags |= nsIResProtocolHandler::ALLOW_CONTENT_ACCESS;
+  }
+  rv = rph->SetSubstitutionWithFlags(host, resolved, substitutionFlags);
+  if (NS_FAILED(rv)) {
+    LogMessageWithContext(cx.GetManifestURI(), lineno,
+                          nsIScriptError::warningFlag,
+                          "Warning: cannot set substitution for '%s'.", uri);
+  }
+}