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

content/shell/renderer/webkit_test_runner.cc

Index: content/shell/renderer/webkit_test_runner.cc
diff --git a/content/shell/renderer/webkit_test_runner.cc b/content/shell/renderer/webkit_test_runner.cc
index 666cd53c35e5412b056db09a282f1c7c6b9d300d..5d939e133ae151a247bf500e5049a6eff325a8c4 100644
--- a/content/shell/renderer/webkit_test_runner.cc
+++ b/content/shell/renderer/webkit_test_runner.cc
@@ -309,10 +309,10 @@ WebURL WebKitTestRunner::rewriteLayoutTestsURL(const std::string& utf8_url) {
       ShellRenderProcessObserver::GetInstance()->webkit_source_dir().Append(
           FILE_PATH_LITERAL("LayoutTests/"));
 #if defined(OS_WIN)
-  std::string utf8_path = WideToUTF8(replace_path.value());
+  std::string utf8_path = base::WideToUTF8(replace_path.value());
 #else
   std::string utf8_path =
-      WideToUTF8(base::SysNativeMBToWide(replace_path.value()));
+      base::WideToUTF8(base::SysNativeMBToWide(replace_path.value()));
 #endif
   std::string new_url =
       std::string("file://") + utf8_path + utf8_url.substr(kPrefixLen);