Ensure ResourceScheduler starts requests even if the tab is closed.

content/browser/loader/resource_scheduler.cc

 // Copyright (c) 2012 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 <set>
 
 #include "content/browser/loader/resource_scheduler.h"
 
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
@@ skipping 329 matching lines @@
       pending_requests_.Erase(request);
       DCHECK(!ContainsKey(in_flight_requests_, request));
     } else {
       EraseInFlightRequest(request);
 
       // Removing this request may have freed up another to load.
       LoadAnyStartablePendingRequests();
     }
   }
 
-  RequestSet RemoveAllRequests() {
+  RequestSet StartAndRemoveAllRequests() {
+    // First start any pending requests so that they will be moved into
+    // in_flight_requests_. This may exceed the limits
+    // kMaxNumDelayableRequestsPerClient, kMaxNumDelayableRequestsPerHost and
+    // kMaxNumThrottledRequestsPerClient, so this method must not do anything
+    // that depends on those limits before calling ClearInFlightRequests()
+    // below.
+    while (!pending_requests_.IsEmpty()) {
+      ScheduledResourceRequest* request =
+          *pending_requests_.GetNextHighestIterator();
+      pending_requests_.Erase(request);
+      // StartRequest() may modify pending_requests_. TODO(ricea): Does it?
+      StartRequest(request);
+    }
     RequestSet unowned_requests;
     for (RequestSet::iterator it = in_flight_requests_.begin();
          it != in_flight_requests_.end(); ++it) {
       unowned_requests.insert(*it);
       (*it)->set_classification(NORMAL_REQUEST);
     }
     ClearInFlightRequests();
     return unowned_requests;
   }
 
@@ skipping 591 matching lines @@
 
 void ResourceScheduler::OnClientDeleted(int child_id, int route_id) {
   DCHECK(CalledOnValidThread());
   ClientId client_id = MakeClientId(child_id, route_id);
   DCHECK(ContainsKey(client_map_, client_id));
   ClientMap::iterator it = client_map_.find(client_id);
   if (it == client_map_.end())
     return;
 
   Client* client = it->second;
-  // FYI, ResourceDispatcherHost cancels all of the requests after this function
-  // is called. It should end up canceling all of the requests except for a
-  // cross-renderer navigation.
-  RequestSet client_unowned_requests = client->RemoveAllRequests();
+  // ResourceDispatcherHost cancels all requests except for cross-renderer
+  // navigations, async revalidations and detachable requests after
+  // OnClientDeleted() returns.
+  RequestSet client_unowned_requests = client->StartAndRemoveAllRequests();
   for (RequestSet::iterator it = client_unowned_requests.begin();
        it != client_unowned_requests.end(); ++it) {
     unowned_requests_.insert(*it);
   }
 
   delete client;
   client_map_.erase(it);
 }
 
 void ResourceScheduler::OnLoadingStateChanged(int child_id,
@@ skipping 213 matching lines @@
   client->ReprioritizeRequest(
       request, old_priority_params, new_priority_params);
 }
 
 ResourceScheduler::ClientId ResourceScheduler::MakeClientId(
     int child_id, int route_id) {
   return (static_cast<ResourceScheduler::ClientId>(child_id) << 32) | route_id;
 }
 
 }  // namespace content