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

content/browser/media/webrtc_aecdump_browsertest.cc

Index: content/browser/media/webrtc_aecdump_browsertest.cc
diff --git a/content/browser/media/webrtc_aecdump_browsertest.cc b/content/browser/media/webrtc_aecdump_browsertest.cc
index 5ba5a85d6787a71acb9a6f43e6608b87b96ad0cd..bda90c93ac25de7466b69678106908a08b9d8f77 100644
--- a/content/browser/media/webrtc_aecdump_browsertest.cc
+++ b/content/browser/media/webrtc_aecdump_browsertest.cc
@@ -53,7 +53,7 @@ class WebrtcAecDumpBrowserTest : 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());
   }