Bug 1676152 - Generalize StructuredCloneHolder::WriteString to accept a nsAString. r=baku

Differential Revision: https://phabricator.services.mozilla.com/D96415

dom/base/StructuredCloneHolder.cpp

@@ -481,10 +481,11 @@ bool StructuredCloneHolder::ReadString(JSStructuredCloneReader* aReader,
 
 /* static */
 bool StructuredCloneHolder::WriteString(JSStructuredCloneWriter* aWriter,
-                                        const nsString& aString) {
+                                        const nsAString& aString) {
   size_t charSize = sizeof(nsString::char_type);
   return JS_WriteUint32Pair(aWriter, aString.Length(), 0) &&
-         JS_WriteBytes(aWriter, aString.get(), aString.Length() * charSize);
+         JS_WriteBytes(aWriter, aString.BeginReading(),
+                       aString.Length() * charSize);
 }
 
 namespace {

dom/base/StructuredCloneHolder.h

@@ -296,7 +296,7 @@ class StructuredCloneHolder : public StructuredCloneHolderBase {
   // Helper functions for reading and writing strings.
   static bool ReadString(JSStructuredCloneReader* aReader, nsString& aString);
   static bool WriteString(JSStructuredCloneWriter* aWriter,
-                          const nsString& aString);
+                          const nsAString& aString);
 
   static const JSStructuredCloneCallbacks sCallbacks;