Rollback of r14496 in trunk branch.

src/frames.h

Index: src/frames.h
diff --git a/src/frames.h b/src/frames.h
index 30ccf388f8b9032bb0bc1c085cde4be2bc3fd666..678191b950a0172a37f62a78fb9533f977502613 100644
--- a/src/frames.h
+++ b/src/frames.h
@@ -969,11 +969,9 @@ typedef JavaScriptFrameIteratorTemp<SafeStackFrameIterator>
 
 class SafeStackTraceFrameIterator: public SafeJavaScriptFrameIterator {
  public:
-  SafeStackTraceFrameIterator(Isolate* isolate,
-                              Address fp,
-                              Address sp,
-                              Address low_bound,
-                              Address high_bound);
+  explicit SafeStackTraceFrameIterator(Isolate* isolate,
+                                       Address fp, Address sp,
+                                       Address low_bound, Address high_bound);
   void Advance();
 };