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

content/browser/media/webrtc_browsertest.cc

Index: content/browser/media/webrtc_browsertest.cc
diff --git a/content/browser/media/webrtc_browsertest.cc b/content/browser/media/webrtc_browsertest.cc
index 5e3666c5f06f91de19265d9d12fc4ffd585379cd..af7b0872f30a5edb95562c6ae04b167d467fcfa5 100644
--- a/content/browser/media/webrtc_browsertest.cc
+++ b/content/browser/media/webrtc_browsertest.cc
@@ -224,7 +224,7 @@ class WebrtcBrowserTest: public ContentBrowserTest {
   }
 
   void ExpectTitle(const std::string& expected_title) const {
-    base::string16 expected_title16(ASCIIToUTF16(expected_title));
+    base::string16 expected_title16(base::ASCIIToUTF16(expected_title));
     TitleWatcher title_watcher(shell()->web_contents(), expected_title16);
     EXPECT_EQ(expected_title16, title_watcher.WaitAndGetTitle());
   }