Convert string16 to base::string16 in content.

content/public/browser/access_token_store.h

Index: content/public/browser/access_token_store.h
diff --git a/content/public/browser/access_token_store.h b/content/public/browser/access_token_store.h
index 0af3fe788823d5266e932b1bf7ba384f94b411a2..bd130144c6c41b7421ebdf16767fa99d03690783 100644
--- a/content/public/browser/access_token_store.h
+++ b/content/public/browser/access_token_store.h
@@ -33,7 +33,7 @@ namespace content {
 class AccessTokenStore : public base::RefCountedThreadSafe<AccessTokenStore> {
  public:
   // Map of server URLs to associated access token.
-  typedef std::map<GURL, string16> AccessTokenSet;
+  typedef std::map<GURL, base::string16> AccessTokenSet;
   typedef base::Callback<void(AccessTokenSet, net::URLRequestContextGetter*)>
       LoadAccessTokensCallbackType;
 
@@ -47,7 +47,7 @@ class AccessTokenStore : public base::RefCountedThreadSafe<AccessTokenStore> {
       const LoadAccessTokensCallbackType& callback) = 0;
 
   virtual void SaveAccessToken(
-      const GURL& server_url, const string16& access_token) = 0;
+      const GURL& server_url, const base::string16& access_token) = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<AccessTokenStore>;