Fix typo inside comment in base/bind_helpers.h.

base/bind_helpers.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This defines a set of argument wrappers and related factory methods that
 // can be used specify the refcounting and reference semantics of arguments
 // that are bound by the Bind() function in base/bind.h.
 //
 // It also defines a set of simple functions and utilities that people want
 // when using Callback<> and Bind().
 //
 //
 // ARGUMENT BINDING WRAPPERS
 //
-// The wrapper functions are base::Unretained(), base::Owned(), bass::Passed(),
+// The wrapper functions are base::Unretained(), base::Owned(), base::Passed(),
 // base::ConstRef(), and base::IgnoreResult().
 //
 // Unretained() allows Bind() to bind a non-refcounted class, and to disable
 // refcounting on arguments that are refcounted objects.
 //
 // Owned() transfers ownership of an object to the Callback resulting from
 // bind; the object will be deleted when the Callback is deleted.
 //
 // Passed() is for transferring movable-but-not-copyable types (eg. scoped_ptr)
 // through a Callback. Logically, this signifies a destructive transfer of
@@ skipping 509 matching lines @@
 BASE_EXPORT void DoNothing();
 
 template<typename T>
 void DeletePointer(T* obj) {
   delete obj;
 }
 
 }  // namespace base
 
 #endif  // BASE_BIND_HELPERS_H_