Add FilePath to base namespace.

chrome/browser/platform_util_android.cc

Index: chrome/browser/platform_util_android.cc
diff --git a/chrome/browser/platform_util_android.cc b/chrome/browser/platform_util_android.cc
index b938f5db84ace973a104e8abc965e09f11170782..e29bea88dda97169b247d8aded43383b99d270a6 100644
--- a/chrome/browser/platform_util_android.cc
+++ b/chrome/browser/platform_util_android.cc
@@ -10,11 +10,11 @@ namespace platform_util {
 
 // TODO: crbug/115682 to track implementation of the following methods.
 
-void ShowItemInFolder(const FilePath& full_path) {
+void ShowItemInFolder(const base::FilePath& full_path) {
   NOTIMPLEMENTED();
 }
 
-void OpenItem(const FilePath& full_path) {
+void OpenItem(const base::FilePath& full_path) {
   NOTIMPLEMENTED();
 }