Grow new gen (1M -> 4M -> 16M on 32-bit) when there is little garbage.

runtime/vm/heap.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/heap.h"
 
 #include "platform/assert.h"
 #include "platform/utils.h"
 #include "vm/flags.h"
 #include "vm/isolate.h"
@@ skipping 15 matching lines @@
 DEFINE_FLAG(int, verbose_gc_hdr, 40, "Print verbose GC header interval.");
 DEFINE_FLAG(bool, verify_before_gc, false,
             "Enables heap verification before GC.");
 DEFINE_FLAG(bool, verify_after_gc, false,
             "Enables heap verification after GC.");
 DEFINE_FLAG(bool, gc_at_alloc, false, "GC at every allocation.");
 DEFINE_FLAG(int, new_gen_ext_limit, 64,
             "maximum total external size (MB) in new gen before triggering GC");
 
 Heap::Heap(Isolate* isolate,
-           intptr_t max_new_gen_words,
+           intptr_t max_new_gen_semi_words,
            intptr_t max_old_gen_words)
     : isolate_(isolate), read_only_(false), gc_in_progress_(false) {
   for (int sel = 0;
        sel < kNumWeakSelectors;
        sel++) {
     new_weak_tables_[sel] = new WeakTable();
     old_weak_tables_[sel] = new WeakTable();
   }
   new_space_ = new Scavenger(this,
-                             max_new_gen_words,
+                             max_new_gen_semi_words,
                              kNewObjectAlignmentOffset);
   old_space_ = new PageSpace(this, max_old_gen_words);
   stats_.num_ = 0;
 }
 
 
 Heap::~Heap() {
   delete new_space_;
   delete old_space_;
   for (int sel = 0;
@@ skipping 521 matching lines @@
     heap->DisableGrowthControl();
 }
 
 
 NoHeapGrowthControlScope::~NoHeapGrowthControlScope() {
     Heap* heap = reinterpret_cast<Isolate*>(isolate())->heap();
     heap->SetGrowthControlState(current_growth_controller_state_);
 }
 
 }  // namespace dart