WIP: Create a LongStringCollection that transfers long strings with fewer copies.

third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp

Index: third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp b/third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp
index 5bfb83bff350d9776245bb18d52f7c1106b2847e..fa91128138fb91c81506953788aacfbe513cf9ba 100644
--- a/third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/serialization/V8ScriptValueSerializer.cpp
@@ -46,10 +46,14 @@ V8ScriptValueSerializer::V8ScriptValueSerializer(
     RefPtr<ScriptState> scriptState,
     const Options& options)
     : m_scriptState(std::move(scriptState)),
-      m_serializedScriptValue(SerializedScriptValue::create()),
+      m_serializedScriptValue(
+          SerializedScriptValue::create(options.longStringPolicy)),
       m_serializer(m_scriptState->isolate(), this),
       m_transferables(options.transferables),
-      m_blobInfoArray(options.blobInfo) {}
+      m_blobInfoArray(options.blobInfo) {
+  m_serializer.SetMinimumLongStringLength(
+      options.longStringPolicy.minimumLength());
+}
 
 RefPtr<SerializedScriptValue> V8ScriptValueSerializer::serialize(
     v8::Local<v8::Value> value,
@@ -420,6 +424,12 @@ v8::Maybe<uint32_t> V8ScriptValueSerializer::GetSharedArrayBufferId(
   return v8::Just<uint32_t>(index);
 }
 
+v8::Maybe<uint32_t> V8ScriptValueSerializer::GetLongStringId(
+    v8::Isolate* isolate,
+    v8::Local<v8::String> string) {
+  return v8::Just(m_serializedScriptValue->m_longStrings.put(isolate, string));
+}
+
 void* V8ScriptValueSerializer::ReallocateBufferMemory(void* oldBuffer,
                                                       size_t size,
                                                       size_t* actualSize) {