Treat weak references in context weakly in write barrier.

src/bootstrapper.cc

 // Copyright 2014 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/bootstrapper.h"
 
 #include "src/accessors.h"
 #include "src/api-natives.h"
 #include "src/base/utils/random-number-generator.h"
 #include "src/code-stubs.h"
@@ skipping 772 matching lines @@
   { // NOLINT
     DCHECK(context->get(Context::NEXT_CONTEXT_LINK)->IsUndefined());
     // Check that context is not in the list yet.
     for (Object* current = heap->native_contexts_list();
          !current->IsUndefined();
          current = Context::cast(current)->get(Context::NEXT_CONTEXT_LINK)) {
       DCHECK(current != context);
     }
   }
 #endif
-  context->set(Context::NEXT_CONTEXT_LINK, heap->native_contexts_list());
+  context->set(Context::NEXT_CONTEXT_LINK, heap->native_contexts_list(),
+               UPDATE_WEAK_WRITE_BARRIER);
   heap->set_native_contexts_list(context);
 }
 
 
 void Genesis::CreateRoots() {
   // Allocate the native context FixedArray first and then patch the
   // closure and extension object later (we need the empty function
   // and the global object, but in order to create those, we need the
   // native context).
   native_context_ = factory()->NewNativeContext();
@@ skipping 2277 matching lines @@
   return from + sizeof(NestingCounterType);
 }
 
 
 // Called when the top-level V8 mutex is destroyed.
 void Bootstrapper::FreeThreadResources() {
   DCHECK(!IsActive());
 }
 
 } }  // namespace v8::internal