--- a/layout/build/nsLayoutStatics.cpp
+++ b/layout/build/nsLayoutStatics.cpp
@@ -127,16 +127,17 @@ using namespace mozilla::system;
 #include "mozilla/IMEStateManager.h"
 #include "mozilla/dom/HTMLVideoElement.h"
 #include "TouchManager.h"
 #include "MediaDecoder.h"
 #include "MediaPrefs.h"
 #include "mozilla/ServoBindings.h"
 #include "mozilla/StaticPresData.h"
 #include "mozilla/dom/WebIDLGlobalNameHash.h"
+#include "mozilla/URLExtraData.h"
 
 using namespace mozilla;
 using namespace mozilla::net;
 using namespace mozilla::dom;
 using namespace mozilla::dom::ipc;
 
 nsrefcnt nsLayoutStatics::sLayoutStaticRefcnt = 0;
 
@@ -307,17 +308,18 @@ nsLayoutStatics::Initialize()
 
   MediaDecoder::InitStatics();
 
   PromiseDebugging::Init();
 
   mozilla::dom::WebCryptoThreadPool::Initialize();
 
 #ifdef MOZ_STYLO
-  Servo_Initialize();
+  URLExtraData::InitDummy();
+  Servo_Initialize(URLExtraData::Dummy());
 #endif
 
 #ifndef MOZ_WIDGET_ANDROID
   // On Android, we instantiate it when constructing AndroidBridge.
   MediaPrefs::GetSingleton();
 #endif
 
   return NS_OK;
@@ -326,16 +328,17 @@ nsLayoutStatics::Initialize()
 void
 nsLayoutStatics::Shutdown()
 {
   // Don't need to shutdown nsWindowMemoryReporter, that will be done by the
   // memory reporter manager.
 
 #ifdef MOZ_STYLO
   Servo_Shutdown();
+  URLExtraData::ReleaseDummy();
 #endif
 
   nsMessageManagerScriptExecutor::Shutdown();
   nsFocusManager::Shutdown();
 #ifdef MOZ_XUL
   nsXULPopupManager::Shutdown();
 #endif
   StorageObserver::Shutdown();

--- a/layout/style/ServoBindingList.h
+++ b/layout/style/ServoBindingList.h
@@ -281,17 +281,18 @@ SERVO_BINDING_FUNC(Servo_ComputedValues_
                    ServoComputedValuesBorrowedOrNull parent_style_or_null,
                    nsIAtom* pseudoTag, bool skip_display_fixup,
                    RawServoStyleSetBorrowed set)
 SERVO_BINDING_FUNC(Servo_ComputedValues_Inherit, ServoComputedValuesStrong,
                    RawServoStyleSetBorrowed set,
                    ServoComputedValuesBorrowedOrNull parent_style)
 
 // Initialize Servo components. Should be called exactly once at startup.
-SERVO_BINDING_FUNC(Servo_Initialize, void)
+SERVO_BINDING_FUNC(Servo_Initialize, void,
+                   RawGeckoURLExtraData* dummy_url_data)
 // Shut down Servo components. Should be called exactly once at shutdown.
 SERVO_BINDING_FUNC(Servo_Shutdown, void)
 
 // Gets the snapshot for the element. This will return null if the element
 // has never been styled, since snapshotting in that case is wasted work.
 SERVO_BINDING_FUNC(Servo_Element_GetSnapshot, ServoElementSnapshot*,
                    RawGeckoElementBorrowed element)
 

--- a/layout/style/ServoBindings.cpp
+++ b/layout/style/ServoBindings.cpp
@@ -2,17 +2,16 @@
 /* vim: set ts=8 sts=2 et sw=2 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/ServoBindings.h"
 
 #include "ChildIterator.h"
-#include "NullPrincipalURI.h"
 #include "gfxFontFamilyList.h"
 #include "nsAnimationManager.h"
 #include "nsAttrValueInlines.h"
 #include "nsCSSFrameConstructor.h"
 #include "nsCSSProps.h"
 #include "nsCSSParser.h"
 #include "nsCSSPseudoElements.h"
 #include "nsCSSRuleProcessor.h"
@@ -1622,25 +1621,16 @@ Gecko_LoadStyleSheet(css::Loader* aLoade
     // silently do nothing.  Eventually we should be able to assert that the
     // NS_NewURI succeeds, here.
     return;
   }
 
   aLoader->LoadChildSheet(aParent, uri, media, nullptr, aChildSheet, nullptr);
 }
 
-RawGeckoURLExtraData*
-Gecko_URLExtraData_CreateDummy()
-{
-  RefPtr<URLExtraData> data = new URLExtraData(NullPrincipalURI::Create(),
-                                               nullptr,
-                                               NullPrincipal::Create());
-  return data.forget().take();
-}
-
 const nsMediaFeature*
 Gecko_GetMediaFeatures()
 {
   return nsMediaFeatures::features;
 }
 
 nsCSSFontFaceRule*
 Gecko_CSSFontFaceRule_Create()

--- a/layout/style/ServoBindings.h
+++ b/layout/style/ServoBindings.h
@@ -114,20 +114,16 @@ void Gecko_LoadStyleSheet(mozilla::css::
                           mozilla::ServoStyleSheet* parent,
                           RawServoStyleSheetBorrowed child_sheet,
                           RawGeckoURLExtraData* base_url_data,
                           const uint8_t* url_bytes,
                           uint32_t url_length,
                           const uint8_t* media_bytes,
                           uint32_t media_length);
 
-// URLExtraData
-// Create a new addrefed URLExtraData.
-RawGeckoURLExtraData* Gecko_URLExtraData_CreateDummy();
-
 // By default, Servo walks the DOM by traversing the siblings of the DOM-view
 // first child. This generally works, but misses anonymous children, which we
 // want to traverse during styling. To support these cases, we create an
 // optional heap-allocated iterator for nodes that need it. If the creation
 // method returns null, Servo falls back to the aforementioned simpler (and
 // faster) sibling traversal.
 StyleChildrenIteratorOwnedOrNull Gecko_MaybeCreateStyleChildrenIterator(RawGeckoNodeBorrowed node);
 void Gecko_DropStyleChildrenIterator(StyleChildrenIteratorOwned it);

--- a/layout/style/URLExtraData.cpp
+++ b/layout/style/URLExtraData.cpp
@@ -4,19 +4,36 @@
  * 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/. */
 
 /* thread-safe container of information for resolving url values */
 
 #include "mozilla/URLExtraData.h"
 
 #include "nsProxyRelease.h"
+#include "NullPrincipalURI.h"
 
 namespace mozilla {
 
+StaticRefPtr<URLExtraData> URLExtraData::sDummy;
+
+/* static */ void
+URLExtraData::InitDummy()
+{
+  sDummy = new URLExtraData(NullPrincipalURI::Create(),
+                            nullptr,
+                            NullPrincipal::Create());
+}
+
+/* static */ void
+URLExtraData::ReleaseDummy()
+{
+  sDummy = nullptr;
+}
+
 URLExtraData::~URLExtraData()
 {
   if (!NS_IsMainThread()) {
     NS_ReleaseOnMainThread(mBaseURI.forget());
     NS_ReleaseOnMainThread(mReferrer.forget());
     NS_ReleaseOnMainThread(mPrincipal.forget());
   }
 }

--- a/layout/style/URLExtraData.h
+++ b/layout/style/URLExtraData.h
@@ -5,16 +5,17 @@
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
 /* thread-safe container of information for resolving url values */
 
 #ifndef mozilla_URLExtraData_h
 #define mozilla_URLExtraData_h
 
 #include "mozilla/Move.h"
+#include "mozilla/StaticPtr.h"
 
 #include "nsCOMPtr.h"
 #include "nsIPrincipal.h"
 #include "nsIURI.h"
 
 namespace mozilla {
 
 struct URLExtraData
@@ -35,19 +36,28 @@ struct URLExtraData
                    do_AddRef(aPrincipal)) {}
 
   NS_INLINE_DECL_THREADSAFE_REFCOUNTING(URLExtraData)
 
   nsIURI* BaseURI() const { return mBaseURI; }
   nsIURI* GetReferrer() const { return mReferrer; }
   nsIPrincipal* GetPrincipal() const { return mPrincipal; }
 
+  static URLExtraData* Dummy() {
+    MOZ_ASSERT(sDummy);
+    return sDummy;
+  }
+  static void InitDummy();
+  static void ReleaseDummy();
+
 private:
   ~URLExtraData();
 
   nsCOMPtr<nsIURI> mBaseURI;
   nsCOMPtr<nsIURI> mReferrer;
   nsCOMPtr<nsIPrincipal> mPrincipal;
+
+  static StaticRefPtr<URLExtraData> sDummy;
 };
 
 } // namespace mozilla
 
 #endif // mozilla_URLExtraData_h