Add FilePath to base namespace.

chrome/browser/history/top_sites.h

Index: chrome/browser/history/top_sites.h
diff --git a/chrome/browser/history/top_sites.h b/chrome/browser/history/top_sites.h
index e87f25d0940519bd8ba6955aea434b9382308662..7ea4fa60f41e170d4cfd9d006c685130357b905f 100644
--- a/chrome/browser/history/top_sites.h
+++ b/chrome/browser/history/top_sites.h
@@ -29,10 +29,10 @@
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/gfx/image/image.h"
 
-class FilePath;
 class Profile;
 
 namespace base {
+class FilePath;
 class RefCountedBytes;
 class RefCountedMemory;
 }
@@ -57,7 +57,7 @@ class TopSites
   explicit TopSites(Profile* profile);
 
   // Initializes TopSites.
-  void Init(const FilePath& db_name);
+  void Init(const base::FilePath& db_name);
 
   // Sets the given thumbnail for the given URL. Returns true if the thumbnail
   // was updated. False means either the URL wasn't known to us, or we felt