3 files changed, 25 insertions, 18 deletions
diff --git a/dom/base/nsContentUtils.cpp b/dom/base/nsContentUtils.cpp
index 34c7d23b8..8612e76df 100644
--- a/dom/base/nsContentUtils.cpp
+++ b/dom/base/nsContentUtils.cpp
@@ -9787,3 +9787,19 @@ nsContentUtils::AttemptLargeAllocationLoad(nsIHttpChannel* aChannel)
 
   return reloadSucceeded;
 }
+
+/* static */ bool
+nsContentUtils::IsLocalRefURL(const nsString& aString)
+{
+  // Find the first non-"C0 controls + space" character.
+  const char16_t* current = aString.get();
+  for (; *current != '\0'; current++) {
+    if (*current > 0x20) {
+      // if the first non-"C0 controls + space" character is '#', this is a
+      // local-ref URL.
+      return *current == '#';
+    }
+  }
+
+  return false;
+}
+\ No newline at end of file
diff --git a/dom/base/nsContentUtils.h b/dom/base/nsContentUtils.h
index 9ae6d2155..c255f813a 100644
--- a/dom/base/nsContentUtils.h
+++ b/dom/base/nsContentUtils.h
@@ -2730,6 +2730,13 @@ public:
 
   static bool AttemptLargeAllocationLoad(nsIHttpChannel* aChannel);
 
+  /**
+   * Detect whether a string is a (CSS) local-url.
+   * https://drafts.csswg.org/css-values/#local-urls
+   */
+  static bool
+  IsLocalRefURL(const nsString& aString);
+
 private:
   static bool InitializeEventTable();
 
diff --git a/layout/style/nsCSSValue.cpp b/layout/style/nsCSSValue.cpp
index baf5b7897..e9c391737 100644
--- a/layout/style/nsCSSValue.cpp
+++ b/layout/style/nsCSSValue.cpp
@@ -29,22 +29,6 @@
 
 using namespace mozilla;
 
-static bool
-IsLocalRefURL(nsStringBuffer* aString)
-{
-  // Find the first non-"C0 controls + space" character.
-  char16_t* current = static_cast<char16_t*>(aString->Data());
-  for (; *current != '\0'; current++) {
-    if (*current > 0x20) {
-      // if the first non-"C0 controls + space" character is '#', this is a
-      // local-ref URL.
-      return *current == '#';
-    }
-  }
-
-  return false;
-}
-
 nsCSSValue::nsCSSValue(int32_t aValue, nsCSSUnit aUnit)
   : mUnit(aUnit)
 {
@@ -2723,7 +2707,7 @@ css::URLValueData::URLValueData(already_AddRefed<PtrHolder<nsIURI>> aURI,
   , mReferrer(Move(aReferrer))
   , mOriginPrincipal(Move(aOriginPrincipal))
   , mURIResolved(true)
-  , mIsLocalRef(IsLocalRefURL(aString))
+  , mIsLocalRef(nsContentUtils::IsLocalRefURL(aString))
 {
   MOZ_ASSERT(mString);
   MOZ_ASSERT(mBaseURI);
@@ -2740,7 +2724,7 @@ css::URLValueData::URLValueData(nsStringBuffer* aString,
   , mReferrer(Move(aReferrer))
   , mOriginPrincipal(Move(aOriginPrincipal))
   , mURIResolved(false)
-  , mIsLocalRef(IsLocalRefURL(aString))
+  , mIsLocalRef(nsContentUtils::IsLocalRefURL(aString))
 {
   MOZ_ASSERT(aString);
   MOZ_ASSERT(mBaseURI);