Push version 1.3.4 to trunk....

src/v8.cc

 // Copyright 2006-2009 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 138 matching lines @@
   // them on demand.
   if (hi == 0) hi = random();
   if (lo == 0) lo = random();
 
   // Mix the bits.
   hi = 36969 * (hi & 0xFFFF) + (hi >> 16);
   lo = 18273 * (lo & 0xFFFF) + (lo >> 16);
   return (hi << 16) + (lo & 0xFFFF);
 }
 
+void V8::IdleNotification(bool is_high_priority) {
+  if (!FLAG_use_idle_notification) return;
+  // Ignore high priority instances of V8.
+  if (is_high_priority) return;
+
+  // Uncommit unused memory in new space.
+  Heap::UncommitFromSpace();
+}
+
 
 Smi* V8::RandomPositiveSmi() {
   uint32_t random = Random();
   ASSERT(IsPowerOf2(Smi::kMaxValue + 1));
   return Smi::FromInt(random & Smi::kMaxValue);
 }
 
 } }  // namespace v8::internal