Use base namespace for string16 in chrome/renderer.

chrome/renderer/translate/translate_helper.cc

Index: chrome/renderer/translate/translate_helper.cc
diff --git a/chrome/renderer/translate/translate_helper.cc b/chrome/renderer/translate/translate_helper.cc
index 08fb3d1034f949c83446929ef415d11de23ecccd..661375899e5bf18c20c5271c977f27fcc5462acb 100644
--- a/chrome/renderer/translate/translate_helper.cc
+++ b/chrome/renderer/translate/translate_helper.cc
@@ -77,7 +77,8 @@ TranslateHelper::~TranslateHelper() {
   CancelPendingTranslation();
 }
 
-void TranslateHelper::PageCaptured(int page_id, const string16& contents) {
+void TranslateHelper::PageCaptured(int page_id,
+                                   const base::string16& contents) {
   // Get the document language as set by WebKit from the http-equiv
   // meta tag for "content-language".  This may or may not also
   // have a value derived from the actual Content-Language HTTP