Attempt to fix GC mole failures.

src/heap/heap.cc

 // 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.
 
 #include "src/v8.h"
 
 #include "src/accessors.h"
 #include "src/api.h"
 #include "src/base/bits.h"
 #include "src/base/once.h"
@@ skipping 2812 matching lines @@
   // is set to avoid expanding the dictionary during bootstrapping.
   set_non_monomorphic_cache(*UnseededNumberDictionary::New(isolate(), 64));
 
   set_polymorphic_code_cache(PolymorphicCodeCache::cast(
       *factory->NewStruct(POLYMORPHIC_CODE_CACHE_TYPE)));
 
   set_instanceof_cache_function(Smi::FromInt(0));
   set_instanceof_cache_map(Smi::FromInt(0));
   set_instanceof_cache_answer(Smi::FromInt(0));
 
-#define SYMBOL_INIT(name) \
-  roots_[k##name##RootIndex] = *factory->NewPrivateOwnSymbol();
-  PRIVATE_SYMBOL_LIST(SYMBOL_INIT)
+  {
+    HandleScope scope(isolate());
+#define SYMBOL_INIT(name)                               \
+  Handle<Symbol> name = factory->NewPrivateOwnSymbol(); \
+  roots_[k##name##RootIndex] = *name;
+    PRIVATE_SYMBOL_LIST(SYMBOL_INIT)
 #undef SYMBOL_INIT
+  }
 
   CreateFixedStubs();
 
   // Allocate the dictionary of intrinsic function names.
   Handle<NameDictionary> intrinsic_names =
       NameDictionary::New(isolate(), Runtime::kNumFunctions, TENURED);
   Runtime::InitializeIntrinsicFunctionNames(isolate(), intrinsic_names);
   set_intrinsic_function_names(*intrinsic_names);
 
   set_number_string_cache(
@@ skipping 3295 matching lines @@
       static_cast<int>(object_sizes_last_time_[index]));
   CODE_AGE_LIST_COMPLETE(ADJUST_LAST_TIME_OBJECT_COUNT)
 #undef ADJUST_LAST_TIME_OBJECT_COUNT
 
   MemCopy(object_counts_last_time_, object_counts_, sizeof(object_counts_));
   MemCopy(object_sizes_last_time_, object_sizes_, sizeof(object_sizes_));
   ClearObjectStats();
 }
 }
 }  // namespace v8::internal