This CL is due the thread I have made on chromium-dev:...

base/stack_container.h

Index: base/stack_container.h
===================================================================
--- base/stack_container.h	(revision 3911)
+++ base/stack_container.h	(working copy)
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/basictypes.h"
+#include "base/thread_collision_warner.h"
 
 // This allocator can be used with STL containers to provide a stack buffer
 // from which to allocate memory and overflows onto the heap. This stack buffer
@@ -152,8 +153,14 @@
   // Support operator-> to get to the container. This allows nicer syntax like:
   //   StackContainer<...> foo;
   //   std::sort(foo->begin(), foo->end());
-  ContainerType* operator->() { return &container_; }
-  const ContainerType* operator->() const { return &container_; }
+  ContainerType* operator->() {
+    D_BOOK_CRITICAL_SECTION(arrow_operator_);
+    return &container_;
+  }
+  const ContainerType* operator->() const {
+    D_BOOK_CRITICAL_SECTION(arrow_operator_);
+    return &container_;
+  }
 
 #ifdef UNIT_TEST
   // Retrieves the stack source so that that unit tests can verify that the
@@ -168,6 +175,8 @@
   Allocator allocator_;
   ContainerType container_;
 
+  D_DEFINE_CRITICAL_SECTION(arrow_operator_);
+
   DISALLOW_EVIL_CONSTRUCTORS(StackContainer);
 };