Treat links that organize weak objects weakly.

src/deoptimizer.cc

 // Copyright 2013 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/codegen.h"
 #include "src/cpu-profiler.h"
 #include "src/deoptimizer.h"
@@ skipping 242 matching lines @@
   while (!element->IsUndefined()) {
     JSFunction* function = JSFunction::cast(element);
     Object* next = function->next_function_link();
     if (function->code()->kind() != Code::OPTIMIZED_FUNCTION ||
         (visitor->VisitFunction(function),
          function->code()->kind() != Code::OPTIMIZED_FUNCTION)) {
       // The function no longer refers to optimized code, or the visitor
       // changed the code to which it refers to no longer be optimized code.
       // Remove the function from this list.
       if (prev != NULL) {
-        prev->set_next_function_link(next);
+        prev->set_next_function_link(next, UPDATE_WEAK_WRITE_BARRIER);
       } else {
         context->SetOptimizedFunctionsListHead(next);
       }
       // The visitor should not alter the link directly.
       CHECK_EQ(function->next_function_link(), next);
       // Set the next function link to undefined to indicate it is no longer
       // in the optimized functions list.
-      function->set_next_function_link(context->GetHeap()->undefined_value());
+      function->set_next_function_link(context->GetHeap()->undefined_value(),
+                                       SKIP_WRITE_BARRIER);
     } else {
       // The visitor should not alter the link directly.
       CHECK_EQ(function->next_function_link(), next);
       // preserve this element.
       prev = function;
     }
     element = next;
   }
 
   visitor->LeaveContext(context);
@@ skipping 3558 matching lines @@
       int raw_position = static_cast<int>(info->data());
       last_position = raw_position ? SourcePosition::FromRaw(raw_position)
                                    : SourcePosition::Unknown();
     } else if (info->rmode() == RelocInfo::DEOPT_REASON) {
       last_reason = static_cast<Deoptimizer::DeoptReason>(info->data());
     }
   }
   return DeoptInfo(SourcePosition::Unknown(), NULL, Deoptimizer::kNoReason);
 }
 } }  // namespace v8::internal