New heap profiler: implement fast retaining sizes approximation.

src/api.cc

Index: src/api.cc
diff --git a/src/api.cc b/src/api.cc
index 083859d3e985aa900da860120819cf4a015c6242..b46cd02a3a706aecb255187faad49ad3a9b783cc 100644
--- a/src/api.cc
+++ b/src/api.cc
@@ -4763,15 +4763,9 @@ int HeapGraphNode::GetSelfSize() const {
 }
 
 
-int HeapGraphNode::GetReachableSize() const {
-  IsDeadCheck("v8::HeapSnapshot::GetReachableSize");
-  return ToInternal(this)->ReachableSize();
-}
-
-
-int HeapGraphNode::GetRetainedSize() const {
+int HeapGraphNode::GetRetainedSize(bool exact) const {
   IsDeadCheck("v8::HeapSnapshot::GetRetainedSize");
-  return ToInternal(this)->RetainedSize();
+  return ToInternal(this)->RetainedSize(exact);
 }
 
 
@@ -4814,6 +4808,12 @@ const HeapGraphPath* HeapGraphNode::GetRetainingPath(int index) const {
 }
 
 
+const HeapGraphNode* HeapGraphNode::GetDominatorNode() const {
+  IsDeadCheck("v8::HeapSnapshot::GetDominatorNode");
+  return reinterpret_cast<const HeapGraphNode*>(ToInternal(this)->dominator());
+}
+
+
 const HeapGraphNode* HeapSnapshotsDiff::GetAdditionsRoot() const {
   IsDeadCheck("v8::HeapSnapshotsDiff::GetAdditionsRoot");
   i::HeapSnapshotsDiff* diff =