Add FilePath to base namespace.

chrome/browser/chromeos/drive/drive_webapps_registry.h

Index: chrome/browser/chromeos/drive/drive_webapps_registry.h
diff --git a/chrome/browser/chromeos/drive/drive_webapps_registry.h b/chrome/browser/chromeos/drive/drive_webapps_registry.h
index 68270794efeab52977ce9eb13a8d7558fde5c3f8..e907db55e23990f87a53d1af1d710886c041c9b2 100644
--- a/chrome/browser/chromeos/drive/drive_webapps_registry.h
+++ b/chrome/browser/chromeos/drive/drive_webapps_registry.h
@@ -13,7 +13,9 @@
 #include "chrome/browser/google_apis/gdata_wapi_parser.h"
 #include "googleurl/src/gurl.h"
 
+namespace base {
 class FilePath;
+}
 
 namespace google_apis {
 class AppList;
@@ -57,7 +59,7 @@ class DriveWebAppsRegistry {
   virtual ~DriveWebAppsRegistry();
 
   // DriveWebAppsRegistry overrides.
-  virtual void GetWebAppsForFile(const FilePath& file,
+  virtual void GetWebAppsForFile(const base::FilePath& file,
                                  const std::string& mime_type,
                                  ScopedVector<DriveWebAppInfo>* apps);
   virtual std::set<std::string> GetExtensionsForWebStoreApp(