Implement prologue weak persistent handles.

runtime/vm/verifier.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "vm/verifier.h"
 
 #include "platform/assert.h"
 #include "vm/dart.h"
 #include "vm/dart_api_state.h"
 #include "vm/freelist.h"
@@ skipping 23 matching lines @@
           !Dart::vm_isolate()->heap()->Contains(obj_addr)) {
         FATAL1("Invalid object pointer encountered 0x%lx\n", obj_addr);
       }
       raw_obj->Validate();
     }
   }
 }
 
 
 void VerifyWeakPointersVisitor::VisitHandle(uword addr) {
-  WeakPersistentHandle* handle = reinterpret_cast<WeakPersistentHandle*>(addr);
+  FinalizablePersistentHandle* handle =
+      reinterpret_cast<FinalizablePersistentHandle*>(addr);
   RawObject* raw_obj = handle->raw();
   visitor_->VisitPointer(&raw_obj);
 }
 
 
 void VerifyPointersVisitor::VerifyPointers() {
   NoGCScope no_gc;
   Isolate* isolate = Isolate::Current();
   VerifyPointersVisitor visitor;
+  // Visit all strongly reachable objects.
   isolate->VisitObjectPointers(&visitor,
+                               false,  // skip prologue weak handles
                                StackFrameIterator::kValidateFrames);
   VerifyWeakPointersVisitor weak_visitor(&visitor);
-  isolate->VisitWeakPersistentHandles(&weak_visitor);
+  // Visit weak handles and prologue weak handles.
+  isolate->VisitWeakPersistentHandles(&weak_visitor,
+                                      true);  // visit prologue weak handles
 }
 
 }  // namespace dart