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

src/isolate-inl.h

Index: src/isolate-inl.h
diff --git a/src/isolate-inl.h b/src/isolate-inl.h
index 5e2c8c25652018fd51ee8e7a069ce23457d61109..45076f565786c095f29cc4d2039b71ef80c12e42 100644
--- a/src/isolate-inl.h
+++ b/src/isolate-inl.h
@@ -28,9 +28,9 @@
 #ifndef V8_ISOLATE_INL_H_
 #define V8_ISOLATE_INL_H_
 
-#include "isolate.h"
-
 #include "debug.h"
+#include "isolate.h"
+#include "utils/random-number-generator.h"
 
 namespace v8 {
 namespace internal {
@@ -67,6 +67,13 @@ bool Isolate::DebuggerHasBreakPoints() {
 }
 
 
+RandomNumberGenerator* Isolate::random_number_generator() {
+  if (random_number_generator_ == NULL) {
+    random_number_generator_ = new RandomNumberGenerator;
+  }
+  return random_number_generator_;
+}
+
 } }  // namespace v8::internal
 
 #endif  // V8_ISOLATE_INL_H_