diff --git a/src/heap.cc b/src/heap.cc
index 32d751a..f88ebda 100644
--- a/src/heap.cc
+++ b/src/heap.cc
@@ -35,6 +35,7 @@
 #include "debug.h"
 #include "heap-profiler.h"
 #include "global-handles.h"
+#include "liveobjectlist-inl.h"
 #include "mark-compact.h"
 #include "natives.h"
 #include "objects-visiting.h"
@@ -400,6 +401,8 @@
 #if defined(DEBUG) || defined(ENABLE_LOGGING_AND_PROFILING)
   ReportStatisticsBeforeGC();
 #endif
+
+  LiveObjectList::GCPrologue();
 }
 
 intptr_t Heap::SizeOfObjects() {
@@ -412,6 +415,7 @@
 }
 
 void Heap::GarbageCollectionEpilogue() {
+  LiveObjectList::GCEpilogue();
 #ifdef DEBUG
   allow_allocation(true);
   ZapFromSpace();
@@ -1066,6 +1070,8 @@
   UpdateNewSpaceReferencesInExternalStringTable(
       &UpdateNewSpaceReferenceInExternalStringTableEntry);
 
+  LiveObjectList::UpdateReferencesForScavengeGC();
+
   ASSERT(new_space_front == new_space_.top());
 
   // Set age mark.
@@ -1820,6 +1826,12 @@
   }
   set_shared_function_info_map(Map::cast(obj));
 
+  { MaybeObject* maybe_obj = AllocateMap(JS_MESSAGE_OBJECT_TYPE,
+                                         JSMessageObject::kSize);
+    if (!maybe_obj->ToObject(&obj)) return false;
+  }
+  set_message_object_map(Map::cast(obj));
+
   ASSERT(!Heap::InNewSpace(Heap::empty_fixed_array()));
   return true;
 }
@@ -1931,6 +1943,14 @@
 }
 
 
+#if V8_TARGET_ARCH_ARM
+void Heap::CreateDirectCEntryStub() {
+  DirectCEntryStub stub;
+  set_direct_c_entry_code(*stub.GetCode());
+}
+#endif
+
+
 void Heap::CreateFixedStubs() {
   // Here we create roots for fixed stubs. They are needed at GC
   // for cooking and uncooking (check out frames.cc).
@@ -1951,6 +1971,9 @@
 #if V8_TARGET_ARCH_ARM && !V8_INTERPRETED_REGEXP
   Heap::CreateRegExpCEntryStub();
 #endif
+#if V8_TARGET_ARCH_ARM
+  Heap::CreateDirectCEntryStub();
+#endif
 }
 
 
@@ -2323,6 +2346,32 @@
 }
 
 
+MaybeObject* Heap::AllocateJSMessageObject(String* type,
+                                           JSArray* arguments,
+                                           int start_position,
+                                           int end_position,
+                                           Object* script,
+                                           Object* stack_trace,
+                                           Object* stack_frames) {
+  Object* result;
+  { MaybeObject* maybe_result = Allocate(message_object_map(), NEW_SPACE);
+    if (!maybe_result->ToObject(&result)) return maybe_result;
+  }
+  JSMessageObject* message = JSMessageObject::cast(result);
+  message->set_properties(Heap::empty_fixed_array());
+  message->set_elements(Heap::empty_fixed_array());
+  message->set_type(type);
+  message->set_arguments(arguments);
+  message->set_start_position(start_position);
+  message->set_end_position(end_position);
+  message->set_script(script);
+  message->set_stack_trace(stack_trace);
+  message->set_stack_frames(stack_frames);
+  return result;
+}
+
+
+
 // Returns true for a character in a range.  Both limits are inclusive.
 static inline bool Between(uint32_t character, uint32_t from, uint32_t to) {
   // This makes uses of the the unsigned wraparound.
@@ -4079,7 +4128,7 @@
 
 #ifdef DEBUG
 void Heap::ZapFromSpace() {
-  ASSERT(reinterpret_cast<Object*>(kFromSpaceZapValue)->IsHeapObject());
+  ASSERT(reinterpret_cast<Object*>(kFromSpaceZapValue)->IsFailure());
   for (Address a = new_space_.FromSpaceLow();
        a < new_space_.FromSpaceHigh();
        a += kPointerSize) {