Fix precache issue with cancel and resume

components/precache/core/precache_fetcher.cc

 // Copyright 2013 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/precache/core/precache_fetcher.h"
 
 #include <algorithm>
 #include <limits>
 #include <utility>
 #include <vector>
@@ skipping 391 matching lines @@
 
 PrecacheFetcher::~PrecacheFetcher() {
 }
 
 std::unique_ptr<PrecacheUnfinishedWork> PrecacheFetcher::CancelPrecaching() {
   // This could get called multiple times, and it should be handled gracefully.
   if (!unfinished_work_)
     return nullptr;
 
   unfinished_work_->clear_resource();
-  if (top_hosts_to_fetch_.size()) {
+  if (unfinished_work_->has_config_settings()) {

[sclittle, 2016/09/02 18:47:56]

Could you add a test for this behavior, e.g. when top_hosts_to_fetch_ is
non-empty but unfinished_work_->has_config_settings() is false?

That'll help prevent regressions.

[Raj, 2016/09/15 17:02:25]

Done.

     // If config fetch is incomplete, |top_hosts_to_fetch_| will be empty and
     // top hosts should be left as is in |unfinished_work_|.
     unfinished_work_->clear_top_host();
     for (const auto& top_host : top_hosts_to_fetch_) {
       unfinished_work_->add_top_host()->set_hostname(top_host.hostname);
     }
   }
   for (const auto& resource : resources_to_fetch_) {
     auto new_resource = unfinished_work_->add_resource();
     new_resource->set_url(resource.first.spec());
@@ skipping 269 matching lines @@
 
 void PrecacheFetcher::UpdateStats(int64_t response_bytes,
                                   int64_t network_response_bytes) {
   unfinished_work_->set_total_bytes(
       unfinished_work_->total_bytes() + response_bytes);
   unfinished_work_->set_network_bytes(
       unfinished_work_->network_bytes() + network_response_bytes);
 }
 
 }  // namespace precache