Make v8::Isolate::SetRAILMode thread safe and remove the

src/isolate.h

 // Copyright 2012 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.
 
 #ifndef V8_ISOLATE_H_
 #define V8_ISOLATE_H_
 
 #include <memory>
 #include <queue>
 #include <set>
@@ skipping 1235 matching lines @@
   bool PropagatePendingExceptionToExternalTryCatch();
 
   // Remove per-frame stored materialized objects when we are unwinding
   // the frame.
   void RemoveMaterializedObjectsOnUnwind(StackFrame* frame);
 
   void RunMicrotasksInternal();
 
   const char* RAILModeName(RAILMode rail_mode) const {
     switch (rail_mode) {
-      case PERFORMANCE_DEFAULT:
-        return "DEFAULT";
       case PERFORMANCE_RESPONSE:
         return "RESPONSE";
       case PERFORMANCE_ANIMATION:
         return "ANIMATION";
       case PERFORMANCE_IDLE:
         return "IDLE";
       case PERFORMANCE_LOAD:
         return "LOAD";
-      default:
-        UNREACHABLE();
     }
     return "";
   }
 
   base::Atomic32 id_;
   EntryStackItem* entry_stack_;
   int stack_trace_nesting_level_;
   StringStream* incomplete_message_;
   Address isolate_addresses_[kIsolateAddressCount + 1];  // NOLINT
   Bootstrapper* bootstrapper_;
@@ skipping 30 matching lines @@
   Builtins builtins_;
   bool has_installed_extensions_;
   unibrow::Mapping<unibrow::Ecma262UnCanonicalize> jsregexp_uncanonicalize_;
   unibrow::Mapping<unibrow::CanonicalizationRange> jsregexp_canonrange_;
   unibrow::Mapping<unibrow::Ecma262Canonicalize>
       regexp_macro_assembler_canonicalize_;
   RegExpStack* regexp_stack_;
   DateCache* date_cache_;
   CallInterfaceDescriptorData* call_descriptor_data_;
   base::RandomNumberGenerator* random_number_generator_;
-  RAILMode rail_mode_;
+  base::AtomicValue<RAILMode> rail_mode_;
 
   // Whether the isolate has been created for snapshotting.
   bool serializer_enabled_;
 
   // True if fatal error has been signaled for this isolate.
   bool has_fatal_error_;
 
   // True if this isolate was initialized from a snapshot.
   bool initialized_from_snapshot_;
 
@@ skipping 315 matching lines @@
 
   EmbeddedVector<char, 128> filename_;
   FILE* file_;
   int scope_depth_;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_H_