Remove legacy StartsWithASCII function.

android_webview/native/android_protocol_handler.cc

Index: android_webview/native/android_protocol_handler.cc
diff --git a/android_webview/native/android_protocol_handler.cc b/android_webview/native/android_protocol_handler.cc
index aaadb14cc2bffdf3007ce0712152fcd716a6ca5d..b9f795ad8da664abd84ee47e96128c746dbf2250 100644
--- a/android_webview/native/android_protocol_handler.cc
+++ b/android_webview/native/android_protocol_handler.cc
@@ -252,8 +252,8 @@ bool AssetFileRequestInterceptor::ShouldHandleRequest(
     return false;
 
   const std::string& url = request->url().spec();
-  if (!base::StartsWithASCII(url, asset_prefix_, /*case_sensitive=*/ true) &&
-      !base::StartsWithASCII(url, resource_prefix_, /*case_sensitive=*/ true)) {
+  if (!base::StartsWith(url, asset_prefix_, base::CompareCase::SENSITIVE) &&
+      !base::StartsWith(url, resource_prefix_, base::CompareCase::SENSITIVE)) {
     return false;
   }