Allow startup with missing V8 snapshot file.

net/proxy/proxy_resolver_v8.cc

 // Copyright (c) 2012 The Chromium 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 "net/proxy/proxy_resolver_v8.h"
 
 #include <algorithm>
 #include <cstdio>
 
 #include "base/auto_reset.h"
@@ skipping 349 matching lines @@
 
   // Lazily creates a v8::Isolate, or returns the already created instance.
   v8::Isolate* GetSharedIsolate() {
     base::AutoLock l(lock_);
 
     if (!holder_) {
       // Do one-time initialization for V8.
       if (!has_initialized_v8_) {
 #ifdef V8_USE_EXTERNAL_STARTUP_DATA
         gin::V8Initializer::LoadV8Snapshot();
+        gin::V8Initializer::LoadV8Natives();
 #endif
 
         gin::IsolateHolder::Initialize(
             gin::IsolateHolder::kNonStrictMode,
             gin::ArrayBufferAllocator::SharedInstance());
 
         has_initialized_v8_ = true;
       }
 
       holder_.reset(new gin::IsolateHolder(gin::IsolateHolder::kUseLocker));
@@ skipping 496 matching lines @@
     return 0;
 
   v8::Locker locked(isolate);
   v8::Isolate::Scope isolate_scope(isolate);
   v8::HeapStatistics heap_statistics;
   isolate->GetHeapStatistics(&heap_statistics);
   return heap_statistics.used_heap_size();
 }
 
 }  // namespace net