Remove request malformed check in password_protection_request

See https://crbug.com/1157814#c3 for the reasoning of this change.

Bug: 1157814
Change-Id: I33a81991fd108ddaf23f5d796941d1347f17ca9b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2589016Reviewed-by: Varun Khaneja <vakh@chromium.org>
Commit-Queue: Xinghui Lu <xinghuilu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#836930}

components/safe_browsing/content/password_protection/password_protection_request.cc

@@ -487,10 +487,8 @@ void PasswordProtectionRequest::SendRequest() {
       WebUIInfoSingleton::GetInstance()->AddToPGPings(*request_proto_);
 
   std::string serialized_request;
-  if (!request_proto_->SerializeToString(&serialized_request)) {
-    Finish(RequestOutcome::REQUEST_MALFORMED, nullptr);
-    return;
-  }
+  // TODO(crbug.com/1158582): Return early if request serialization fails.
+  request_proto_->SerializeToString(&serialized_request);
 
   net::NetworkTrafficAnnotationTag traffic_annotation =
       net::DefineNetworkTrafficAnnotation("password_protection_request", R"(