Add FilePath to base namespace.

printing/printed_document.h

Index: printing/printed_document.h
diff --git a/printing/printed_document.h b/printing/printed_document.h
index bdb092fc3223d6055f138c63c8de9443e75eda61..3992386c294561c42e9a68e12cf4d4c147b383dc 100644
--- a/printing/printed_document.h
+++ b/printing/printed_document.h
@@ -13,9 +13,12 @@
 #include "printing/print_settings.h"
 #include "ui/gfx/native_widget_types.h"
 
-class FilePath;
 class MessageLoop;
 
+namespace base {
+class FilePath;
+}
+
 namespace printing {
 
 class Metafile;
@@ -93,9 +96,9 @@ class PRINTING_EXPORT PrintedDocument
 
   // Sets a path where to dump printing output files for debugging. If never set
   // no files are generated.
-  static void set_debug_dump_path(const FilePath& debug_dump_path);
+  static void set_debug_dump_path(const base::FilePath& debug_dump_path);
 
-  static const FilePath& debug_dump_path();
+  static const base::FilePath& debug_dump_path();
 
  private:
   friend class base::RefCountedThreadSafe<PrintedDocument>;