Reland r24563 and r24564 with fixes cumbersome API leading to leaks.

runtime/vm/pages.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/pages.h"
 
 #include "platform/assert.h"
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
@@ skipping 303 matching lines @@
   }
 
   page = large_pages_;
   while (page != NULL) {
     page->VisitObjects(visitor);
     page = page->next();
   }
 }
 
 
-void PageSpace::SetPeer(RawObject* raw_obj, void* peer) {
-  if (peer == NULL) {
-    peer_table_.erase(raw_obj);
-  } else {
-    peer_table_[raw_obj] = peer;
-  }
-}
-
-
-void* PageSpace::GetPeer(RawObject* raw_obj) {
-  PeerTable::iterator it = peer_table_.find(raw_obj);
-  return (it == peer_table_.end()) ? NULL : it->second;
-}
-
-
-int64_t PageSpace::PeerCount() const {
-  return static_cast<int64_t>(peer_table_.size());
-}
-
-
 void PageSpace::VisitObjectPointers(ObjectPointerVisitor* visitor) const {
   HeapPage* page = pages_;
   while (page != NULL) {
     page->VisitObjectPointers(visitor);
     page = page->next();
   }
 
   page = large_pages_;
   while (page != NULL) {
     page->VisitObjectPointers(visitor);
@@ skipping 252 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result= static_cast<int>((static_cast<double>(gc_time) /
                              static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart