Introduce a RandonNumberGenerator class. Refactor the random/private_random uses in Isolate/Context.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index ca10394f3279265f07842692a9eaefdb215b60ce..bfce95e3d1b8f58ca48dee65a5f093a986600190 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -4729,7 +4729,7 @@ Smi* JSReceiver::GenerateIdentityHash() {
   do {
     // Generate a random 32-bit hash value but limit range to fit
     // within a smi.
-    hash_value = V8::RandomPrivate(isolate) & Smi::kMaxValue;
+    hash_value = isolate->random_number_generator()->NextInt() & Smi::kMaxValue;
     attempts++;
   } while (hash_value == 0 && attempts < 30);
   hash_value = hash_value != 0 ? hash_value : 1;  // never return 0