Handle timeout for update requests.

components/safe_browsing_db/v4_update_protocol_manager.cc

Index: components/safe_browsing_db/v4_update_protocol_manager.cc
diff --git a/components/safe_browsing_db/v4_update_protocol_manager.cc b/components/safe_browsing_db/v4_update_protocol_manager.cc
index 070f4438b580992b2a4a7ebef36eb2d816180be1..b1d468db77fa32d0ecae9f3ee9365747c1877b8e 100644
--- a/components/safe_browsing_db/v4_update_protocol_manager.cc
+++ b/components/safe_browsing_db/v4_update_protocol_manager.cc
@@ -70,6 +70,9 @@ static const int kV4TimerStartIntervalSecMin = 60;
 // Maximum time, in seconds, from start up before we must issue an update query.
 static const int kV4TimerStartIntervalSecMax = 300;
 
+// Maximum time, in seconds, to wait for a response to an update request.
+static const int kV4TimerUpdateWaitSecMax = 30;
+
 // The default V4UpdateProtocolManagerFactory.
 class V4UpdateProtocolManagerFactoryImpl
     : public V4UpdateProtocolManagerFactory {
@@ -248,7 +251,6 @@ bool V4UpdateProtocolManager::ParseUpdateResponse(
         base::TimeDelta::FromSeconds(minimum_wait_duration_seconds);
   }
 
-  // TODO(vakh): Do something useful with this response.
   for (ListUpdateResponse& list_update_response :
        *response.mutable_list_update_responses()) {
     if (!list_update_response.has_platform_type()) {
@@ -293,7 +295,17 @@ void V4UpdateProtocolManager::IssueUpdateRequest() {
   request_->SetLoadFlags(net::LOAD_DISABLE_CACHE);
   request_->SetRequestContext(request_context_getter_.get());
   request_->Start();
-  // TODO(vakh): Handle request timeout.
+
+  // Begin the update request timeout.
+  timeout_timer_.Start(FROM_HERE,
+                       TimeDelta::FromSeconds(kV4TimerUpdateWaitSecMax), this,
+                       &V4UpdateProtocolManager::HandleTimeout);
+}
+
+void V4UpdateProtocolManager::HandleTimeout() {
+  UMA_HISTOGRAM_COUNTS_100("SafeBrowsing.V4Update.Timeout.Count", 1);

[Nathan Parker, 2016/11/08 23:39:29]

Or UMA_HISTOGRAM_BOOLEAN("..", true)
either way

[vakh (use Gerrit instead), 2016/11/09 00:08:51]

Done.

+  request_.reset();
+  ScheduleNextUpdateWithBackoff(false);
 }
 
 // net::URLFetcherDelegate implementation ----------------------------------
@@ -303,6 +315,8 @@ void V4UpdateProtocolManager::OnURLFetchComplete(
     const net::URLFetcher* source) {
   DCHECK(CalledOnValidThread());
 
+  timeout_timer_.Stop();
+
   int response_code = source->GetResponseCode();
   net::URLRequestStatus status = source->GetStatus();
   V4ProtocolManagerUtil::RecordHttpResponseOrErrorCode(