Replace ToLower calls to the new format

android_webview/browser/aw_content_browser_client.cc

Index: android_webview/browser/aw_content_browser_client.cc
diff --git a/android_webview/browser/aw_content_browser_client.cc b/android_webview/browser/aw_content_browser_client.cc
index efbbdbe10f33a296aa74f3ab2301a0cdd32558be..1f598230f287029dd1213573405be7ae7e92507c 100644
--- a/android_webview/browser/aw_content_browser_client.cc
+++ b/android_webview/browser/aw_content_browser_client.cc
@@ -118,7 +118,7 @@ std::string AwContentBrowserClient::GetAcceptLangsImpl() {
 
   // If we're not en-US, add in en-US which will be
   // used with a lower q-value.
-  if (base::StringToLowerASCII(langs) != "en-us") {
+  if (base::ToLowerASCII(langs) != "en-us") {
     langs += ",en-US";
   }
   return langs;