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

chrome/browser/drive/drive_api_util.cc

Index: chrome/browser/drive/drive_api_util.cc
diff --git a/chrome/browser/drive/drive_api_util.cc b/chrome/browser/drive/drive_api_util.cc
index 103458918508031f444bf725de8bebc27c455ab3..610f735afc8cb2c863c801d8cbd33e13386a055c 100644
--- a/chrome/browser/drive/drive_api_util.cc
+++ b/chrome/browser/drive/drive_api_util.cc
@@ -162,7 +162,8 @@ std::string TranslateQuery(const std::string& original_query) {
   // In order to handle non-ascii white spaces correctly, convert to UTF16.
   base::string16 query = base::UTF8ToUTF16(original_query);
   const base::string16 kDelimiter(
-      base::kWhitespaceUTF16 + base::string16(1, static_cast<char16>('"')));
+      base::kWhitespaceUTF16 +
+      base::string16(1, static_cast<base::char16>('"')));
 
   std::string result;
   for (size_t index = query.find_first_not_of(base::kWhitespaceUTF16);