Fix the new generation growth criterion so it is not mislead into performing two growths in a row.

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 345 matching lines @@
 Scavenger::~Scavenger() {
   ASSERT(!scavenging_);
   to_->Delete();
   delete space_lock_;
 }
 
 intptr_t Scavenger::NewSizeInWords(intptr_t old_size_in_words) const {
   if (stats_history_.Size() == 0) {
     return old_size_in_words;
   }
-  double garbage = stats_history_.Get(0).GarbageFraction();
+  double garbage = stats_history_.Get(0).ExpectedGarbageFraction();
   if (garbage < (FLAG_new_gen_garbage_threshold / 100.0)) {
     return Utils::Minimum(max_semi_capacity_in_words_,
                           old_size_in_words * FLAG_new_gen_growth_factor);
   } else {
     return old_size_in_words;
   }
 }
 
 SemiSpace* Scavenger::Prologue(Isolate* isolate) {
   isolate->PrepareForGC();
@@ skipping 572 matching lines @@
   return free_space >> kWordSizeLog2;
 }
 
 int64_t Scavenger::UsedInWords() const {
   int64_t free_space_in_tlab = FreeSpaceInWords(heap_->isolate());
   int64_t max_space_used = (top_ - FirstObjectStart()) >> kWordSizeLog2;
   return max_space_used - free_space_in_tlab;
 }
 
 }  // namespace dart