Zero-sized new-space for VM isolate.

runtime/vm/dart.cc

Index: runtime/vm/dart.cc
===================================================================
--- runtime/vm/dart.cc	(revision 35383)
+++ runtime/vm/dart.cc	(working copy)
@@ -30,6 +30,12 @@
 
 namespace dart {
 
+DEFINE_FLAG(int, new_gen_heap_size, 32, "new gen heap size in MB,"
+            "e.g: --new_gen_heap_size=64 allocates a 64MB new gen heap");
+DEFINE_FLAG(int, old_gen_heap_size, Heap::kHeapSizeInMB,
+            "old gen heap size in MB,"
+            "e.g: --old_gen_heap_size=1024 allocates a 1024MB old gen heap");
+
 DECLARE_FLAG(bool, print_class_table);
 DECLARE_FLAG(bool, trace_isolates);
 
@@ -117,7 +123,9 @@
     vm_isolate_ = Isolate::Init("vm-isolate");
     StackZone zone(vm_isolate_);
     HandleScope handle_scope(vm_isolate_);
-    Heap::Init(vm_isolate_);
+    Heap::Init(vm_isolate_,
+               0,  // New gen size 0; VM isolate should only allocate in old.
+               FLAG_old_gen_heap_size * MBInWords);
     ObjectStore::Init(vm_isolate_);
     TargetCPUFeatures::InitOnce();
     Object::InitOnce();
@@ -203,7 +211,9 @@
   ASSERT(isolate != NULL);
   StackZone zone(isolate);
   HandleScope handle_scope(isolate);
-  Heap::Init(isolate);
+  Heap::Init(isolate,
+             FLAG_new_gen_heap_size * MBInWords,
+             FLAG_old_gen_heap_size * MBInWords);
   ObjectIdRing::Init(isolate);
   ObjectStore::Init(isolate);