- fix some cases where we are using uninitialized memory

runtime/vm/scavenger.cc

 // Copyright (c) 2011, 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/scavenger.h"
 
 #include "vm/dart.h"
 #include "vm/dart_api_state.h"
 #include "vm/isolate.h"
 #include "vm/lockers.h"
@@ skipping 340 matching lines @@
   }
   // Setup local fields.
   top_ = FirstObjectStart();
   resolved_top_ = top_;
   end_ = to_->end();
 
   survivor_end_ = FirstObjectStart();
 
   UpdateMaxHeapCapacity();
   UpdateMaxHeapUsage();
-  if (heap_ != NULL) {
-    heap_->UpdateGlobalMaxUsed();
-  }
 }
 
 
 Scavenger::~Scavenger() {
   ASSERT(!scavenging_);
   to_->Delete();
 }
 
 
 intptr_t Scavenger::NewSizeInWords(intptr_t old_size_in_words) const {
@@ skipping 529 matching lines @@
 }
 
 
 void Scavenger::FreeExternal(intptr_t size) {
   ASSERT(size >= 0);
   external_size_ -= size;
   ASSERT(external_size_ >= 0);
 }
 
 }  // namespace dart