Use base namespace for string16 in chrome/renderer.

chrome/renderer/autofill/password_autofill_agent_browsertest.cc

Index: chrome/renderer/autofill/password_autofill_agent_browsertest.cc
diff --git a/chrome/renderer/autofill/password_autofill_agent_browsertest.cc b/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
index 94f2af7ca0b1e92503480bb04e763a16f0a79a61..9877b27360ce8db27ed50721cadc5714f1a110b8 100644
--- a/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
+++ b/chrome/renderer/autofill/password_autofill_agent_browsertest.cc
@@ -308,13 +308,13 @@ class PasswordAutofillAgentTest : public ChromeRenderViewTest {
     EXPECT_EQ(end, username_element_.selectionEnd());
   }
 
-  string16 username1_;
-  string16 username2_;
-  string16 username3_;
-  string16 password1_;
-  string16 password2_;
-  string16 password3_;
-  string16 alternate_username3_;
+  base::string16 username1_;
+  base::string16 username2_;
+  base::string16 username3_;
+  base::string16 password1_;
+  base::string16 password2_;
+  base::string16 password3_;
+  base::string16 alternate_username3_;
   PasswordFormFillData fill_data_;
 
   WebInputElement username_element_;