Add FilePath to base namespace.

chrome/installer/util/master_preferences.h

Index: chrome/installer/util/master_preferences.h
diff --git a/chrome/installer/util/master_preferences.h b/chrome/installer/util/master_preferences.h
index 46dc7c97b34ad4a642450bd34077aea2f2e526fd..773d6031e25fa2b2a8060e54150e09d022c3d41b 100644
--- a/chrome/installer/util/master_preferences.h
+++ b/chrome/installer/util/master_preferences.h
@@ -15,10 +15,9 @@
 #include "base/memory/scoped_ptr.h"
 #include "googleurl/src/gurl.h"
 
-class FilePath;
-
 namespace base {
 class DictionaryValue;
+class FilePath;
 }
 
 namespace installer {
@@ -91,7 +90,7 @@ class MasterPreferences {
 
   // Parses a specific preferences file and does not merge any command line
   // switches with the distribution dictionary.
-  explicit MasterPreferences(const FilePath& prefs_path);
+  explicit MasterPreferences(const base::FilePath& prefs_path);
 
   // Parses a preferences directly from |prefs| and does not merge any command
   // line switches with the distribution dictionary.