[android_webview] Hardcode the default text encoding to UTF-8.

android_webview/renderer/aw_content_renderer_client.cc

Index: android_webview/renderer/aw_content_renderer_client.cc
diff --git a/android_webview/renderer/aw_content_renderer_client.cc b/android_webview/renderer/aw_content_renderer_client.cc
index caa372d8163ba259cee1b510ca553725ad2e4465..7ba28d9044d9c74f09ff1eedd27ddb8aeda27178 100644
--- a/android_webview/renderer/aw_content_renderer_client.cc
+++ b/android_webview/renderer/aw_content_renderer_client.cc
@@ -147,10 +147,6 @@ void AwContentRendererClient::RenderViewCreated(
   new autofill::AutofillAgent(render_view, password_autofill_agent, NULL);
 }
 
-std::string AwContentRendererClient::GetDefaultEncoding() {
-  return AwResource::GetDefaultTextEncoding();
-}
-
 bool AwContentRendererClient::HasErrorPage(int http_status_code,
                           std::string* error_domain) {
   return http_status_code >= 400;