[base] Remove PointersMatch, making a separate std::equals hashmap

src/profiler/heap-snapshot-generator.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/profiler/heap-snapshot-generator.h"
 
 #include "src/code-stubs.h"
 #include "src/conversions.h"
 #include "src/debug/debug.h"
 #include "src/objects-body-descriptors.h"
@@ skipping 337 matching lines @@
 // HeapObjectsMap::GenerateId) and odds for native objects.
 const SnapshotObjectId HeapObjectsMap::kInternalRootObjectId = 1;
 const SnapshotObjectId HeapObjectsMap::kGcRootsObjectId =
     HeapObjectsMap::kInternalRootObjectId + HeapObjectsMap::kObjectIdStep;
 const SnapshotObjectId HeapObjectsMap::kGcRootsFirstSubrootId =
     HeapObjectsMap::kGcRootsObjectId + HeapObjectsMap::kObjectIdStep;
 const SnapshotObjectId HeapObjectsMap::kFirstAvailableObjectId =
     HeapObjectsMap::kGcRootsFirstSubrootId +
     VisitorSynchronization::kNumberOfSyncTags * HeapObjectsMap::kObjectIdStep;
 
-
-static bool AddressesMatch(void* key1, void* key2) {
-  return key1 == key2;
-}
-
-
 HeapObjectsMap::HeapObjectsMap(Heap* heap)
-    : next_id_(kFirstAvailableObjectId),
-      entries_map_(AddressesMatch),
-      heap_(heap) {
+    : next_id_(kFirstAvailableObjectId), entries_map_(), heap_(heap) {

[marja, 2016/09/30 10:27:33]

Since entries_map_ can now use the default ctor, can you remove it from this
line?

[Leszek Swirski, 2016/09/30 10:44:28]

Done.

   // This dummy element solves a problem with entries_map_.
   // When we do lookup in HashMap we see no difference between two cases:
   // it has an entry with NULL as the value or it has created
   // a new entry on the fly with NULL as the default value.
   // With such dummy element we have a guaranty that all entries_map_ entries
   // will have the value field grater than 0.
   // This fact is using in MoveObject method.
   entries_.Add(EntryInfo(0, NULL, 0));
 }
 
@@ skipping 2744 matching lines @@
   for (int i = 1; i < sorted_strings.length(); ++i) {
     writer_->AddCharacter(',');
     SerializeString(sorted_strings[i]);
     if (writer_->aborted()) return;
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8