Update some uses of char16 to use the base:: namespace.

content/browser/dom_storage/session_storage_database.cc

Index: content/browser/dom_storage/session_storage_database.cc
diff --git a/content/browser/dom_storage/session_storage_database.cc b/content/browser/dom_storage/session_storage_database.cc
index 8dc8b91c279bda1748d5753e0f5736c677947596..30d3d86577e8614d6b80cce935646b821fa64922 100644
--- a/content/browser/dom_storage/session_storage_database.cc
+++ b/content/browser/dom_storage/session_storage_database.cc
@@ -578,9 +578,9 @@ bool SessionStorageDatabase::ReadMap(const std::string& map_id,
     } else {
       // Convert the raw data stored in std::string (it->value()) to raw data
       // stored in base::string16.
-      size_t len = it->value().size() / sizeof(char16);
-      const char16* data_ptr =
-          reinterpret_cast<const char16*>(it->value().data());
+      size_t len = it->value().size() / sizeof(base::char16);
+      const base::char16* data_ptr =
+          reinterpret_cast<const base::char16*>(it->value().data());
       (*result)[key16] =
           base::NullableString16(base::string16(data_ptr, len), false);
     }