Domain Reliability: Don't crash on shutdown with uploads pending

components/domain_reliability/uploader.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/domain_reliability/uploader.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback.h"
+#include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/supports_user_data.h"
 #include "components/domain_reliability/util.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_response_headers.h"
 #include "net/http/http_util.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
@@ skipping 30 matching lines @@
 
 class DomainReliabilityUploaderImpl
     : public DomainReliabilityUploader, net::URLFetcherDelegate {
  public:
   DomainReliabilityUploaderImpl(
       MockableTime* time,
       const scoped_refptr<
           net::URLRequestContextGetter>& url_request_context_getter)
       : time_(time),
         url_request_context_getter_(url_request_context_getter),
-        discard_uploads_(true) {}
+        discard_uploads_(true),
+        shutdown_(false) {}
 
-  ~DomainReliabilityUploaderImpl() override {}
+  ~DomainReliabilityUploaderImpl() override {
+    DCHECK(shutdown_);
+  }
 
   // DomainReliabilityUploader implementation:
   void UploadReport(
       const std::string& report_json,
       int max_upload_depth,
       const GURL& upload_url,
       const DomainReliabilityUploader::UploadCallback& callback) override {
     VLOG(1) << "Uploading report to " << upload_url;
     VLOG(2) << "Report JSON: " << report_json;
 
-    if (discard_uploads_) {
+    if (discard_uploads_ || shutdown_) {
       VLOG(1) << "Discarding report instead of uploading.";
       UploadResult result;
       result.status = UploadResult::SUCCESS;
       callback.Run(result);
       return;
     }
 
     std::unique_ptr<net::URLFetcher> owned_fetcher =
         net::URLFetcher::Create(0, upload_url, net::URLFetcher::POST, this);
     net::URLFetcher* fetcher = owned_fetcher.get();
     fetcher->SetRequestContext(url_request_context_getter_.get());
     fetcher->SetLoadFlags(net::LOAD_DO_NOT_SEND_COOKIES |
                           net::LOAD_DO_NOT_SAVE_COOKIES);
     fetcher->SetUploadData(kJsonMimeType, report_json);
     fetcher->SetAutomaticallyRetryOn5xx(false);
     fetcher->SetURLRequestUserData(
         UploadUserData::kUserDataKey,
         UploadUserData::CreateCreateDataCallback(max_upload_depth + 1));
     fetcher->Start();
 
-    upload_callbacks_[fetcher] = {std::move(owned_fetcher), callback};
+    uploads_[fetcher] = {std::move(owned_fetcher), callback};
 
     base::TimeTicks now = base::TimeTicks::Now();
     if (!last_upload_start_time_.is_null()) {
       UMA_HISTOGRAM_LONG_TIMES("DomainReliability.UploadIntervalGlobal",
                                now - last_upload_start_time_);
     }
     last_upload_start_time_ = now;
   }
 
   void set_discard_uploads(bool discard_uploads) override {
     discard_uploads_ = discard_uploads;
     VLOG(1) << "Setting discard_uploads to " << discard_uploads;
   }
 
+  void Shutdown() override {
+    DCHECK(!shutdown_);
+    shutdown_ = true;
+    uploads_.clear();
+  }
+
   // net::URLFetcherDelegate implementation:
   void OnURLFetchComplete(const net::URLFetcher* fetcher) override {
     DCHECK(fetcher);
 
-    auto callback_it = upload_callbacks_.find(fetcher);
-    DCHECK(callback_it != upload_callbacks_.end());
+    auto callback_it = uploads_.find(fetcher);
+    DCHECK(callback_it != uploads_.end());
 
     int net_error = GetNetErrorFromURLRequestStatus(fetcher->GetStatus());
     int http_response_code = fetcher->GetResponseCode();
     base::TimeDelta retry_after;
     {
       std::string retry_after_string;
       if (fetcher->GetResponseHeaders() &&
           fetcher->GetResponseHeaders()->EnumerateHeader(nullptr,
                                                          "Retry-After",
                                                          &retry_after_string)) {
@@ skipping 12 matching lines @@
     UMA_HISTOGRAM_SPARSE_SLOWLY("DomainReliability.UploadNetError",
                                 -net_error);
 
     UploadResult result;
     GetUploadResultFromResponseDetails(net_error,
                                        http_response_code,
                                        retry_after,
                                        &result);
     callback_it->second.second.Run(result);
 
-    upload_callbacks_.erase(callback_it);
+    uploads_.erase(callback_it);
   }
 
  private:
   using DomainReliabilityUploader::UploadCallback;
 
   MockableTime* time_;
   scoped_refptr<net::URLRequestContextGetter> url_request_context_getter_;
   std::map<const net::URLFetcher*,
            std::pair<std::unique_ptr<net::URLFetcher>, UploadCallback>>
-      upload_callbacks_;
+      uploads_;
   bool discard_uploads_;
   base::TimeTicks last_upload_start_time_;
+  bool shutdown_;
 };
 
 }  // namespace
 
 DomainReliabilityUploader::DomainReliabilityUploader() {}
 DomainReliabilityUploader::~DomainReliabilityUploader() {}
 
 // static
 std::unique_ptr<DomainReliabilityUploader> DomainReliabilityUploader::Create(
     MockableTime* time,
@@ skipping 12 matching lines @@
 // static
 int DomainReliabilityUploader::GetURLRequestUploadDepth(
     const net::URLRequest& request) {
   UploadUserData* data = static_cast<UploadUserData*>(
       request.GetUserData(UploadUserData::kUserDataKey));
   if (!data)
     return 0;
   return data->depth();
 }
 
+void DomainReliabilityUploader::Shutdown() {}
+
 }  // namespace domain_reliability