Add FilePath to base namespace.

base/file_version_info.h

Index: base/file_version_info.h
diff --git a/base/file_version_info.h b/base/file_version_info.h
index 84eec41b450678fd8fcf973e2694b88ddc1eab6e..bffa322e25a45c62731d8bf1f167e6772a6d59f3 100644
--- a/base/file_version_info.h
+++ b/base/file_version_info.h
@@ -18,7 +18,9 @@ extern "C" IMAGE_DOS_HEADER __ImageBase;
 #include "base/base_export.h"
 #include "base/string16.h"
 
+namespace base {
 class FilePath;
+}
 
 // Provides an interface for accessing the version information for a file. This
 // is the information you access when you select a file in the Windows Explorer,
@@ -38,7 +40,7 @@ class FileVersionInfo {
   // goes wrong (typically the file does not exit or cannot be opened). The
   // returned object should be deleted when you are done with it.
   BASE_EXPORT static FileVersionInfo* CreateFileVersionInfo(
-      const FilePath& file_path);
+      const base::FilePath& file_path);
 #endif  // OS_WIN || OS_MACOSX
 
 #if defined(OS_WIN)