Update some uses of UTF conversions in chrome/browser to use the base:: namespace.

chrome/browser/autocomplete/extension_app_provider.cc

Index: chrome/browser/autocomplete/extension_app_provider.cc
diff --git a/chrome/browser/autocomplete/extension_app_provider.cc b/chrome/browser/autocomplete/extension_app_provider.cc
index 0998d7e9b5f06471b0db8aa80f97c42b9a05ea90..88efea6bcf5d99c106c4db0a274eae5d59636c7a 100644
--- a/chrome/browser/autocomplete/extension_app_provider.cc
+++ b/chrome/browser/autocomplete/extension_app_provider.cc
@@ -173,8 +173,8 @@ void ExtensionAppProvider::RefreshAppList() {
     DCHECK(launch_url.is_valid());
 
     ExtensionApp extension_app = {
-        UTF8ToUTF16(app->name()),
-        UTF8ToUTF16(launch_url.spec()),
+        base::UTF8ToUTF16(app->name()),
+        base::UTF8ToUTF16(launch_url.spec()),
         // Only hosted apps have recognizable URLs that users might type in,
         // packaged apps and hosted apps use chrome-extension:// URLs that are
         // normally not shown to users.