[Webview, Child Accounts] Automatically sign in to Chrome if needed.

chrome/browser/supervised_user/supervised_user_content_provider_android.cc

Index: chrome/browser/supervised_user/supervised_user_content_provider_android.cc
diff --git a/chrome/browser/supervised_user/supervised_user_content_provider_android.cc b/chrome/browser/supervised_user/supervised_user_content_provider_android.cc
index e328d08fd9cd6809553c1f8753bbb84c8f088a3e..f98fea463f5ebc7b2a87b53112dc3e3d8c20bcb7 100644
--- a/chrome/browser/supervised_user/supervised_user_content_provider_android.cc
+++ b/chrome/browser/supervised_user/supervised_user_content_provider_android.cc
@@ -70,8 +70,12 @@ void SupervisedUserContentProvider::ShouldProceed(
     const JavaParamRef<jobject>& query_result_jobj,
     const JavaParamRef<jstring>& url) {
   if (!profile_->IsSupervised()) {
-    // User isn't supervised
-    Java_SupervisedUserQueryReply_onQueryComplete(env, query_result_jobj);
+    // User isn't supervised, this can only happen if Chrome isn't signed in,
+    // in which case all requests should be rejected
+    Java_SupervisedUserQueryReply_onQueryFailed(
+        AttachCurrentThread(), query_result_jobj,
+        supervised_user_error_page::NOT_SIGNED_IN, false, true, nullptr,
+        nullptr, nullptr, nullptr, nullptr, nullptr);
     return;
   }
   SupervisedUserService* supervised_user_service =