Run load state update timer only when needed

content/browser/loader/resource_dispatcher_host_impl.cc

Index: content/browser/loader/resource_dispatcher_host_impl.cc
diff --git a/content/browser/loader/resource_dispatcher_host_impl.cc b/content/browser/loader/resource_dispatcher_host_impl.cc
index 2e560f635d57729e21d66f439e226ec29f8e7604..cc871f65fe95f6fcffa845631f2a35d78d4a45d2 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -115,7 +115,7 @@ namespace {
 static ResourceDispatcherHostImpl* g_resource_dispatcher_host;
 
 // The interval for calls to ResourceDispatcherHostImpl::UpdateLoadStates
-const int kUpdateLoadStatesIntervalMsec = 100;
+const int kUpdateLoadStatesIntervalMsec = 250;
 
 // Maximum byte "cost" of all the outstanding requests for a renderer.
 // See delcaration of |max_outstanding_requests_cost_per_process_| for details.
@@ -453,7 +453,7 @@ ResourceDispatcherHostImpl::ResourceDispatcherHostImpl()
                                      base::Unretained(this)));
 
   update_load_states_timer_.reset(
-      new base::RepeatingTimer<ResourceDispatcherHostImpl>());
+      new base::OneShotTimer<ResourceDispatcherHostImpl>());
 }
 
 ResourceDispatcherHostImpl::~ResourceDispatcherHostImpl() {
@@ -788,12 +788,8 @@ bool ResourceDispatcherHostImpl::HandleExternalProtocol(ResourceLoader* loader,
 }
 
 void ResourceDispatcherHostImpl::DidStartRequest(ResourceLoader* loader) {
-  // Make sure we have the load state monitor running
-  if (!update_load_states_timer_->IsRunning()) {
-    update_load_states_timer_->Start(
-        FROM_HERE, TimeDelta::FromMilliseconds(kUpdateLoadStatesIntervalMsec),
-        this, &ResourceDispatcherHostImpl::UpdateLoadInfo);
-  }
+  if (scheduler_->HasLoadingClients())
+    ScheduleUpdateLoadInfo();
 }
 
 void ResourceDispatcherHostImpl::DidReceiveRedirect(ResourceLoader* loader,
@@ -940,7 +936,7 @@ void ResourceDispatcherHostImpl::OnShutdown() {
 
   // Make sure we shutdown the timer now, otherwise by the time our destructor
   // runs if the timer is still running the Task is deleted twice (once by
-  // the MessageLoop and the second time by RepeatingTimer).
+  // the MessageLoop and the second time by OneShotTimer).
   update_load_states_timer_.reset();
 
   // Clear blocked requests if any left.
@@ -1781,10 +1777,6 @@ void ResourceDispatcherHostImpl::RemovePendingLoader(
   IncrementOutstandingRequestsMemory(-1, *info);
 
   pending_loaders_.erase(iter);
-
-  // If we have no more pending requests, then stop the load state monitor
-  if (pending_loaders_.empty() && update_load_states_timer_)
-    update_load_states_timer_->Stop();
 }
 
 void ResourceDispatcherHostImpl::CancelRequest(int child_id,
@@ -2179,10 +2171,6 @@ ResourceDispatcherHostImpl::GetLoadInfoForAllRoutes() {
   scoped_ptr<LoadInfoMap> info_map(new LoadInfoMap());
 
   for (const auto& loader : pending_loaders_) {

[mmenke, 2015/05/21 15:53:25]

Should actually remove this call in the other CL.

[Andre, 2015/05/21 22:05:39]

Done.

-    // Also poll for upload progress on this timer and send upload progress ipc
-    // messages to the plugin process.
-    loader.second->ReportUploadProgress();
-
     net::URLRequest* request = loader.second->request();
     net::UploadProgress upload_progress = request->GetUploadProgress();
 
@@ -2213,6 +2201,9 @@ void ResourceDispatcherHostImpl::UpdateLoadInfo() {
       BrowserThread::UI, FROM_HERE,
       base::Bind(&ResourceDispatcherHostImpl::UpdateLoadInfoOnUIThread,
                  base::Passed(&info_map)));
+
+  if (scheduler_->HasLoadingClients())
+     ScheduleUpdateLoadInfo();

[mmenke, 2015/05/21 15:53:25]

Should use 2 space indent here, not 3

[Andre, 2015/05/21 22:05:39]

Done.

 }
 
 void ResourceDispatcherHostImpl::BlockRequestsForRoute(int child_id,
@@ -2375,4 +2366,12 @@ int ResourceDispatcherHostImpl::BuildLoadFlagsForRequest(
   return load_flags;
 }
 
+void ResourceDispatcherHostImpl::ScheduleUpdateLoadInfo() {
+  if (!update_load_states_timer_->IsRunning()) {

[mmenke, 2015/05/21 15:53:25]

Suggest early return instead - it's generally preferred.

[Andre, 2015/05/21 22:05:39]

Done.

+    update_load_states_timer_->Start(
+        FROM_HERE, TimeDelta::FromMilliseconds(kUpdateLoadStatesIntervalMsec),
+        this, &ResourceDispatcherHostImpl::UpdateLoadInfo);
+  }
+}
+
 }  // namespace content