Serializer: move to a subfolder and clean up includes.

src/snapshot-external.cc

-// Copyright 2006-2008 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.
-
-// Used for building with external snapshots.
-
-#include "src/snapshot.h"
-
-#include "src/base/platform/mutex.h"
-#include "src/serialize.h"
-#include "src/snapshot-source-sink.h"
-#include "src/v8.h"  // for V8::Initialize
-
-
-#ifndef V8_USE_EXTERNAL_STARTUP_DATA
-#error snapshot-external.cc is used only for the external snapshot build.
-#endif  // V8_USE_EXTERNAL_STARTUP_DATA
-
-
-namespace v8 {
-namespace internal {
-
-static base::LazyMutex external_startup_data_mutex = LAZY_MUTEX_INITIALIZER;
-static v8::StartupData external_startup_blob = {NULL, 0};
-
-void SetSnapshotFromFile(StartupData* snapshot_blob) {
-  base::LockGuard<base::Mutex> lock_guard(
-      external_startup_data_mutex.Pointer());
-  DCHECK(snapshot_blob);
-  DCHECK(snapshot_blob->data);
-  DCHECK(snapshot_blob->raw_size > 0);
-  DCHECK(!external_startup_blob.data);
-  DCHECK(Snapshot::SnapshotIsValid(snapshot_blob));
-  external_startup_blob = *snapshot_blob;
-}
-
-
-const v8::StartupData* Snapshot::DefaultSnapshotBlob() {
-  base::LockGuard<base::Mutex> lock_guard(
-      external_startup_data_mutex.Pointer());
-  return &external_startup_blob;
-}
-} }  // namespace v8::internal