Move global V8::UseCrankshaft() into the Isolate.

src/v8.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 36 matching lines @@
 
 namespace v8 {
 namespace internal {
 
 V8_DECLARE_ONCE(init_once);
 
 bool V8::is_running_ = false;
 bool V8::has_been_set_up_ = false;
 bool V8::has_been_disposed_ = false;
 bool V8::has_fatal_error_ = false;
-bool V8::use_crankshaft_ = true;
 List<CallCompletedCallback>* V8::call_completed_callbacks_ = NULL;
 v8::ArrayBuffer::Allocator* V8::array_buffer_allocator_ = NULL;
 
 static LazyMutex entropy_mutex = LAZY_MUTEX_INITIALIZER;
 
 static EntropySource entropy_source;
 
 
 bool V8::Initialize(Deserializer* des) {
   InitializeOncePerProcess();
@@ skipping 243 matching lines @@
 
   if (FLAG_concurrent_recompilation &&
       SystemThreadManager::NumberOfParallelSystemThreads(
           SystemThreadManager::PARALLEL_RECOMPILATION) == 0) {
     FLAG_concurrent_recompilation = false;
   }
 
   OS::SetUp();
   Sampler::SetUp();
   CPU::SetUp();
-  use_crankshaft_ = FLAG_crankshaft
-      && !Serializer::enabled()
-      && CPU::SupportsCrankshaft();
   OS::PostSetUp();
   ElementsAccessor::InitializeOncePerProcess();
   LOperand::SetUpCaches();
   SetUpJSCallerSavedCodeData();
   ExternalReference::SetUp();
   Bootstrapper::InitializeOncePerProcess();
 }
 
 
 void V8::InitializeOncePerProcess() {
   CallOnce(&init_once, &InitializeOncePerProcessImpl);
 }
 
 } }  // namespace v8::internal