Protect SerializedData from copying.

src/snapshot/code-serializer.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/snapshot/code-serializer.h"
 
 #include <memory>
 
 #include "src/code-stubs.h"
 #include "src/counters.h"
@@ skipping 467 matching lines @@
 Vector<const uint32_t> SerializedCodeData::CodeStubKeys() const {
   int reservations_size = GetHeaderValue(kNumReservationsOffset) * kInt32Size;
   const byte* start = data_ + kHeaderSize + reservations_size;
   return Vector<const uint32_t>(reinterpret_cast<const uint32_t*>(start),
                                 GetHeaderValue(kNumCodeStubKeysOffset));
 }
 
 SerializedCodeData::SerializedCodeData(ScriptData* data)
     : SerializedData(const_cast<byte*>(data->data()), data->length()) {}
 
-const SerializedCodeData SerializedCodeData::FromCachedData(
+SerializedCodeData SerializedCodeData::FromCachedData(
     Isolate* isolate, ScriptData* cached_data, uint32_t expected_source_hash,
     SanityCheckResult* rejection_result) {
   DisallowHeapAllocation no_gc;
   SerializedCodeData scd(cached_data);
   *rejection_result = scd.SanityCheck(isolate, expected_source_hash);
   if (*rejection_result != CHECK_SUCCESS) {
     cached_data->Reject();
     return SerializedCodeData(nullptr, 0);
   }
   return scd;
 }
 
 }  // namespace internal
 }  // namespace v8