Allows prefetch requests to live beyond the renderer by delaying

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 a44715d3996dcb3d155ea5158b95841b131eab26..b088e1a588793282a5ee922c76af31f7d52d90e0 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -407,12 +407,15 @@ void ResourceDispatcherHostImpl::CancelRequestsForContext(
   for (LoaderList::iterator i = loaders_to_cancel.begin();
        i != loaders_to_cancel.end(); ++i) {
     // There is no strict requirement that this be the case, but currently
-    // downloads, streams  and transferred requests are the only requests that
-    // aren't cancelled when the associated processes go away. It may be OK for
-    // this invariant to change in the future, but if this assertion fires
-    // without the invariant changing, then it's indicative of a leak.
+    // downloads, streams, prefetches, and transferred requests are the only
+    // requests that aren't cancelled when the associated processes go away. It
+    // may be OK for this invariant to change in the future, but if this
+    // assertion fires without the invariant changing, then it's indicative of a
+    // leak.
     DCHECK((*i)->GetRequestInfo()->is_download() ||
            (*i)->GetRequestInfo()->is_stream() ||
+           (*i)->GetRequestInfo()->GetResourceType() ==
+               ResourceType::PREFETCH ||
            (*i)->is_transferring());
   }
 #endif
@@ -1098,7 +1101,14 @@ void ResourceDispatcherHostImpl::BeginRequest(
   if (sync_result) {
     handler.reset(new SyncResourceHandler(request, sync_result, this));
   } else {
-    handler.reset(new AsyncResourceHandler(request, this));
+    AsyncResourceHandler* async_handler =
+        new AsyncResourceHandler(request, this);
+    if (request_data.resource_type == ResourceType::PREFETCH) {
+      // The renderer doesn't need prefetch data notifications and the prefetch
+      // request might live longer than the renderer, so detach reads.
+      async_handler->DetachReads();
+    }
+    handler.reset(async_handler);
   }
 
   // The RedirectToFileResourceHandler depends on being next in the chain.
@@ -1324,8 +1334,8 @@ void ResourceDispatcherHostImpl::ResumeDeferredNavigation(
 }
 
 // The object died, so cancel and detach all requests associated with it except
-// for downloads, which belong to the browser process even if initiated via a
-// renderer.
+// for downloads and prefetches, which belong to the browser process even if
+// initiated via a renderer.
 void ResourceDispatcherHostImpl::CancelRequestsForProcess(int child_id) {
   CancelRequestsForRoute(child_id, -1 /* cancel all */);
   registered_temp_files_.erase(child_id);
@@ -1350,12 +1360,12 @@ void ResourceDispatcherHostImpl::CancelRequestsForRoute(int child_id,
 
     GlobalRequestID id(child_id, i->first.request_id);
     DCHECK(id == i->first);
-
     // Don't cancel navigations that are transferring to another process,
     // since they belong to another process now.
     if (IsTransferredNavigation(id))
       any_requests_transferring = true;
     if (!info->is_download() && !info->is_stream() &&
+        info->GetResourceType() != ResourceType::PREFETCH &&
         !IsTransferredNavigation(id) &&
         (route_id == -1 || route_id == info->GetRouteID())) {
       matching_requests.push_back(id);