Update uses of UTF conversions in content/ to use the base:: namespace.

content/test/mock_google_streaming_server.cc

Index: content/test/mock_google_streaming_server.cc
diff --git a/content/test/mock_google_streaming_server.cc b/content/test/mock_google_streaming_server.cc
index e1b7fdf16bec853a3bd5b416b1392d7f013d2b5f..4eae25c6817383eec17c482da10f297347fe0414 100644
--- a/content/test/mock_google_streaming_server.cc
+++ b/content/test/mock_google_streaming_server.cc
@@ -93,7 +93,7 @@ void MockGoogleStreamingServer::SimulateResult(
         proto_result->add_alternative();
     const SpeechRecognitionHypothesis& hypothesis = result.hypotheses[i];
     proto_alternative->set_confidence(hypothesis.confidence);
-    proto_alternative->set_transcript(UTF16ToUTF8(hypothesis.utterance));
+    proto_alternative->set_transcript(base::UTF16ToUTF8(hypothesis.utterance));
   }
 
   std::string msg_string;