Support profiler stack sampling in any situation.

src/frames-inl.h

Index: src/frames-inl.h
diff --git a/src/frames-inl.h b/src/frames-inl.h
index c9d3ab6b461ff00abd8e5fbc27d44f43e8f203b9..32820a5811f2c5134f5c0afc730ab79cdb990707 100644
--- a/src/frames-inl.h
+++ b/src/frames-inl.h
@@ -169,6 +169,20 @@ inline bool JavaScriptFrame::has_adapted_arguments() const {
 }
 
 
+inline bool JavaScriptFrame::is_at_function() const {
+  Object* result = function_slot_object();
+  return Heap::Contains(reinterpret_cast<Address>(result)) &&
+      result->IsJSFunction();
+}
+
+
+inline Object* JavaScriptFrame::function() const {
+  Object* result = function_slot_object();
+  ASSERT(result->IsJSFunction());
+  return result;
+}
+
+
 template<typename Iterator>
 inline JavaScriptFrame* JavaScriptFrameIteratorTemp<Iterator>::frame() const {
   // TODO(1233797): The frame hierarchy needs to change. It's