HeapProfiler: very slow ~4min "take snapshot time" for 80MB gmail heap.

include/v8-profiler.h

Index: include/v8-profiler.h
diff --git a/include/v8-profiler.h b/include/v8-profiler.h
index d7350db9f372006208a5227ad195cd0595636bf7..217a938329eee70f9483f8d84ef8654c59907a1d 100644
--- a/include/v8-profiler.h
+++ b/include/v8-profiler.h
@@ -246,17 +246,19 @@ class V8_EXPORT HeapGraphEdge {
 class V8_EXPORT HeapGraphNode {
  public:
   enum Type {
-    kHidden = 0,      // Hidden node, may be filtered when shown to user.
-    kArray = 1,       // An array of elements.
-    kString = 2,      // A string.
-    kObject = 3,      // A JS object (except for arrays and strings).
-    kCode = 4,        // Compiled code.
-    kClosure = 5,     // Function closure.
-    kRegExp = 6,      // RegExp.
-    kHeapNumber = 7,  // Number stored in the heap.
-    kNative = 8,      // Native object (not from V8 heap).
-    kSynthetic = 9    // Synthetic object, usualy used for grouping
-                      // snapshot items together.
+    kHidden = 0,        // Hidden node, may be filtered when shown to user.
+    kArray = 1,         // An array of elements.
+    kString = 2,        // A string.
+    kObject = 3,        // A JS object (except for arrays and strings).
+    kCode = 4,          // Compiled code.
+    kClosure = 5,       // Function closure.
+    kRegExp = 6,        // RegExp.
+    kHeapNumber = 7,    // Number stored in the heap.
+    kNative = 8,        // Native object (not from V8 heap).
+    kSynthetic = 9,     // Synthetic object, usualy used for grouping
+                        // snapshot items together.
+    kConsString = 10,   // Concatenated string. A pair of pointers to strings.
+    kSlicedString = 11  // Sliced string. A fragment of another string.
   };
 
   /** Returns node type (see HeapGraphNode::Type). */