Move nullable_string16.h to the string subdirectory.

webkit/renderer/dom_storage/dom_storage_cached_area.h

Index: webkit/renderer/dom_storage/dom_storage_cached_area.h
diff --git a/webkit/renderer/dom_storage/dom_storage_cached_area.h b/webkit/renderer/dom_storage/dom_storage_cached_area.h
index 4cac9c4f1ca0e0d2fbe979bbff0778fa2021f113..c4f075b61170588ace04ba426eb5b53069647ab7 100644
--- a/webkit/renderer/dom_storage/dom_storage_cached_area.h
+++ b/webkit/renderer/dom_storage/dom_storage_cached_area.h
@@ -9,7 +9,7 @@
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/nullable_string16.h"
+#include "base/strings/nullable_string16.h"
 #include "googleurl/src/gurl.h"
 #include "webkit/storage/webkit_storage_export.h"
 
@@ -34,8 +34,8 @@ class WEBKIT_STORAGE_EXPORT DomStorageCachedArea :
   const GURL& origin() const { return origin_; }
 
   unsigned GetLength(int connection_id);
-  NullableString16 GetKey(int connection_id, unsigned index);
-  NullableString16 GetItem(int connection_id, const base::string16& key);
+  base::NullableString16 GetKey(int connection_id, unsigned index);
+  base::NullableString16 GetItem(int connection_id, const base::string16& key);
   bool SetItem(int connection_id,
                const base::string16& key,
                const base::string16& value,
@@ -44,8 +44,8 @@ class WEBKIT_STORAGE_EXPORT DomStorageCachedArea :
                   const GURL& page_url);
   void Clear(int connection_id, const GURL& page_url);
 
-  void ApplyMutation(const NullableString16& key,
-                     const NullableString16& new_value);
+  void ApplyMutation(const base::NullableString16& key,
+                     const base::NullableString16& new_value);
 
   size_t MemoryBytesUsedByCache() const;