Disable flywheel if authentication fails repeatedly.

This will disable DRP for the remainder of the session.
Note that the next time the app starts, WebView will still try to
enale flywheel based on the user preference in Google Settings.

BUG: 17624720
Change-Id: I52926b8f72f99b7c97505d6860e056918addd96c
diff --git a/android_webview/browser/aw_login_delegate.cc b/android_webview/browser/aw_login_delegate.cc
index 9c8a7c1..15ee045 100644
--- a/android_webview/browser/aw_login_delegate.cc
+++ b/android_webview/browser/aw_login_delegate.cc
@@ -120,7 +120,9 @@
     }
     if (drp_result ==
             DataReductionProxyAuthRequestHandler::TRY_HANDLE_RESULT_CANCEL) {
-      Cancel();
+      // Give up. Disable the proxy and retry.
+      drp_settings->SetDataReductionProxyEnabled(false);
+      Proceed(user, password);
       return;
     }
     // Fall through if |drp_result| is IGNORE