Removed unused --preallocate-message-memory flag.

src/isolate.h

Index: src/isolate.h
diff --git a/src/isolate.h b/src/isolate.h
index 1d45de97b8ee88009c9aa8d3183ecc5a3dbbb0d3..3c55883a86aefa802031c5d1b38b1ba8d05236f3 100644
--- a/src/isolate.h
+++ b/src/isolate.h
@@ -76,7 +76,6 @@ class HTracer;
 class InlineRuntimeFunctionsTable;
 class NoAllocationStringAllocator;
 class InnerPointerToCodeCache;
-class PreallocatedMemoryThread;
 class RandomNumberGenerator;
 class RegExpStack;
 class SaveContext;
@@ -331,7 +330,7 @@ class ThreadLocalTop BASE_EMBEDDED {
   V(uint32_t, private_random_seed, 2)                                          \
   ISOLATE_INIT_DEBUG_ARRAY_LIST(V)
 
-typedef List<HeapObject*, PreallocatedStorageAllocationPolicy> DebugObjectCache;
+typedef List<HeapObject*> DebugObjectCache;
 
 #define ISOLATE_INIT_LIST(V)                                                   \
   /* SerializerDeserializer state. */                                          \
@@ -978,10 +977,6 @@ class Isolate {
     return &interp_canonicalize_mapping_;
   }
 
-  void* PreallocatedStorageNew(size_t size);
-  void PreallocatedStorageDelete(void* p);
-  void PreallocatedStorageInit(size_t size);
-
   inline bool IsCodePreAgingActive();
 
 #ifdef ENABLE_DEBUGGER_SUPPORT
@@ -1242,8 +1237,6 @@ class Isolate {
   // at the same time, this should be prevented using external locking.
   void Exit();
 
-  void PreallocatedMemoryThreadStart();
-  void PreallocatedMemoryThreadStop();
   void InitializeThreadLocal();
 
   void PrintStackTrace(FILE* out, ThreadLocalTop* thread);
@@ -1266,10 +1259,7 @@ class Isolate {
   EntryStackItem* entry_stack_;
   int stack_trace_nesting_level_;
   StringStream* incomplete_message_;
-  // The preallocated memory thread singleton.
-  PreallocatedMemoryThread* preallocated_memory_thread_;
   Address isolate_addresses_[kIsolateAddressCount + 1];  // NOLINT
-  NoAllocationStringAllocator* preallocated_message_space_;
   Bootstrapper* bootstrapper_;
   RuntimeProfiler* runtime_profiler_;
   CompilationCache* compilation_cache_;
@@ -1296,9 +1286,6 @@ class Isolate {
   HandleScopeImplementer* handle_scope_implementer_;
   UnicodeCache* unicode_cache_;
   Zone runtime_zone_;
-  PreallocatedStorage in_use_list_;
-  PreallocatedStorage free_list_;
-  bool preallocated_storage_preallocated_;
   InnerPointerToCodeCache* inner_pointer_to_code_cache_;
   ConsStringIteratorOp* write_iterator_;
   GlobalHandles* global_handles_;