Fix precache issue with cancel and resume

components/precache/core/precache_fetcher.cc

Index: components/precache/core/precache_fetcher.cc
diff --git a/components/precache/core/precache_fetcher.cc b/components/precache/core/precache_fetcher.cc
index 90d05bb776b6eb6b841c69369f29a3acc5846c87..a8c30752b5b2b4b63ecd6baf5b43f23e62a64749 100644
--- a/components/precache/core/precache_fetcher.cc
+++ b/components/precache/core/precache_fetcher.cc
@@ -409,7 +409,7 @@ std::unique_ptr<PrecacheUnfinishedWork> PrecacheFetcher::CancelPrecaching() {
     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();