Unbreak unit tests. Revert r7564.

base/file_path.cc

Index: base/file_path.cc
===================================================================
--- base/file_path.cc	(revision 7570)
+++ base/file_path.cc	(working copy)
@@ -113,7 +113,7 @@
   return new_path;
 }
 
-FilePath FilePath::BaseName() const {
+FilePath::StringType FilePath::BaseName() const {
   FilePath new_path(path_);
   new_path.StripTrailingSeparatorsInternal();
 
@@ -133,7 +133,7 @@
     new_path.path_.erase(0, last_separator + 1);
   }
 
-  return new_path;
+  return new_path.path_;
 }
 
 FilePath FilePath::Append(const FilePath::StringType& component) const {