Use conservative hash table capacity growth during entire snapshotting.

src/api.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/api.h"
 
 #include <string.h>  // For memcpy, strlen.
 #ifdef V8_USE_ADDRESS_SANITIZER
 #include <sanitizer/asan_interface.h>
 #endif  // V8_USE_ADDRESS_SANITIZER
@@ skipping 329 matching lines @@
 StartupData V8::CreateSnapshotDataBlob(const char* custom_source) {
   i::Isolate* internal_isolate = new i::Isolate(true);
   ArrayBufferAllocator allocator;
   internal_isolate->set_array_buffer_allocator(&allocator);
   Isolate* isolate = reinterpret_cast<Isolate*>(internal_isolate);
   StartupData result = {NULL, 0};
   {
     base::ElapsedTimer timer;
     timer.Start();
     Isolate::Scope isolate_scope(isolate);
+    internal_isolate->set_creating_default_snapshot(true);
     internal_isolate->Init(NULL);
     Persistent<Context> context;
     i::Snapshot::Metadata metadata;
     {
       HandleScope handle_scope(isolate);
       Handle<Context> new_context = Context::New(isolate);
+      internal_isolate->set_creating_default_snapshot(false);
       context.Reset(isolate, new_context);
       if (custom_source != NULL) {
         metadata.set_embeds_script(true);
         Context::Scope context_scope(new_context);
         if (!RunExtraCode(isolate, custom_source)) context.Reset();
       }
     }
     if (!context.IsEmpty()) {
       // Make sure all builtin scripts are cached.
       {
@@ skipping 7713 matching lines @@
   Isolate* isolate = reinterpret_cast<Isolate*>(info.GetIsolate());
   Address callback_address =
       reinterpret_cast<Address>(reinterpret_cast<intptr_t>(callback));
   VMState<EXTERNAL> state(isolate);
   ExternalCallbackScope call_scope(isolate, callback_address);
   callback(info);
 }
 
 
 } }  // namespace v8::internal