Revert of [Bindings] Create and use V8 context snapshots

third_party/WebKit/Source/core/workers/WorkerBackingThread.cpp

 // Copyright 2016 The Chromium 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 "core/workers/WorkerBackingThread.h"
 
 #include <memory>
 #include "bindings/core/v8/V8BindingForCore.h"
-#include "bindings/core/v8/V8ContextSnapshot.h"
 #include "bindings/core/v8/V8GCController.h"
 #include "bindings/core/v8/V8IdleTaskRunner.h"
 #include "bindings/core/v8/V8Initializer.h"
 #include "core/inspector/WorkerThreadDebugger.h"
 #include "core/workers/WorkerBackingThreadStartupData.h"
 #include "platform/CrossThreadFunctional.h"
 #include "platform/RuntimeEnabledFeatures.h"
 #include "platform/WebThreadSupportingGC.h"
 #include "platform/bindings/V8PerIsolateData.h"
 #include "platform/wtf/PtrUtil.h"
@@ skipping 38 matching lines @@
       should_call_gc_on_shutdown_(should_call_gc_on_shutdown) {}
 
 WorkerBackingThread::~WorkerBackingThread() {}
 
 void WorkerBackingThread::InitializeOnBackingThread(
     const WorkerBackingThreadStartupData& startup_data) {
   DCHECK(backing_thread_->IsCurrentThread());
   backing_thread_->InitializeOnThread();
 
   DCHECK(!isolate_);
-  // TODO(peria): Replace GetReferenceTable with nullptr.
-  // (http://crbug.com/v8/6448)
   isolate_ = V8PerIsolateData::Initialize(
-      backing_thread_->PlatformThread().GetWebTaskRunner(),
-      V8ContextSnapshot::GetReferenceTable(),
-      V8PerIsolateData::V8ContextSnapshotMode::kDontUseSnapshot);
+      backing_thread_->PlatformThread().GetWebTaskRunner());
   AddWorkerIsolate(isolate_);
   V8Initializer::InitializeWorker(isolate_);
 
   ThreadState::Current()->RegisterTraceDOMWrappers(
       isolate_, V8GCController::TraceDOMWrappers,
       ScriptWrappableVisitor::InvalidateDeadObjectsInMarkingDeque,
       ScriptWrappableVisitor::PerformCleanup);
   if (RuntimeEnabledFeatures::V8IdleTasksEnabled())
     V8PerIsolateData::EnableIdleTasks(
         isolate_, WTF::WrapUnique(new V8IdleTaskRunner(
@@ skipping 44 matching lines @@
 
 // static
 void WorkerBackingThread::SetRAILModeOnWorkerThreadIsolates(
     v8::RAILMode rail_mode) {
   MutexLocker lock(IsolatesMutex());
   for (v8::Isolate* isolate : Isolates())
     isolate->SetRAILMode(rail_mode);
 }
 
 }  // namespace blink