Add ObjectMoveEvent reporting for the Heap Profiler into MarkCompact.

R=vegorov@chromium.org
BUG=none
TEST=none

Review URL: http://codereview.chromium.org/8036024

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@9432 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/mark-compact.cc

@@ -2367,6 +2367,7 @@ void MarkCompactCollector::MigrateObject(Address dst,
                                          Address src,
                                          int size,
                                          AllocationSpace dest) {
+  HEAP_PROFILE(heap(), ObjectMoveEvent(src, dst));
   if (dest == OLD_POINTER_SPACE || dest == LO_SPACE) {
     Address src_slot = src;
     Address dst_slot = dst;

src/profile-generator.cc

@@ -1403,10 +1403,12 @@ void HeapObjectsMap::MoveObject(Address from, Address to) {
   if (entry != NULL) {
     void* value = entry->value;
     entries_map_.Remove(from, AddressHash(from));
-    entry = entries_map_.Lookup(to, AddressHash(to), true);
-    // We can have an entry at the new location, it is OK, as GC can overwrite
-    // dead objects with alive objects being moved.
-    entry->value = value;
+    if (to != NULL) {
+      entry = entries_map_.Lookup(to, AddressHash(to), true);
+      // We can have an entry at the new location, it is OK, as GC can overwrite
+      // dead objects with alive objects being moved.
+      entry->value = value;
+    }
   }
 }