Does anyone need copy constructor for StackFrameIterator?

src/frames.cc

Index: src/frames.cc
diff --git a/src/frames.cc b/src/frames.cc
index 24550a2ed07f0afeadd3d062a245d0ea2a36987e..13762b59988c2b32d72d1167a2f04591b79e1b8f 100644
--- a/src/frames.cc
+++ b/src/frames.cc
@@ -91,6 +91,25 @@ StackFrameIterator::StackFrameIterator(bool use_top, Address fp, Address sp)
   JavaScriptFrame_.DisableHeapAccess();
 }
 
+StackFrameIterator::StackFrameIterator(const StackFrameIterator& original)
+    : STACK_FRAME_TYPE_LIST(INITIALIZE_SINGLETON)
+      frame_(NULL) {
+  this->operator=(original);
+}
+
+void StackFrameIterator::operator =(const StackFrameIterator& original) {
+  this->frame_ = this->SingletonFor(original.frame_->type());
+  this->frame_->state_ = original.frame_->state_;
+
+  this->handler_ = original.handler_;
+  this->thread_ = original.thread_;
+  this->fp_ = original.fp_;
+  this->sp_ = original.sp_;
+  this->advance_ = original.advance_;
+  this->JavaScriptFrame_.disable_heap_access_ =
+      original.JavaScriptFrame_.disable_heap_access_;
+}
+
 #undef INITIALIZE_SINGLETON
 
 
@@ -171,6 +190,12 @@ StackFrame* StackFrameIterator::SingletonFor(StackFrame::Type type) {
 }
 
 
+bool operator==(const StackFrameIterator& one,
+    const StackFrameIterator& another) {
+  return one.frame()->id() == another.frame()->id();
+}
+
+
 // -------------------------------------------------------------------------