Allows prefetch requests to live beyond the renderer by delaying

content/browser/loader/resource_loader.cc

Index: content/browser/loader/resource_loader.cc
diff --git a/content/browser/loader/resource_loader.cc b/content/browser/loader/resource_loader.cc
index 88c9c857d55e21cb6b8017de3f08821b32cf8964..d6bf407e25a222df68f802229df345bdc7c12d35 100644
--- a/content/browser/loader/resource_loader.cc
+++ b/content/browser/loader/resource_loader.cc
@@ -7,7 +7,9 @@
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
+#include "base/strings/string_number_conversions.h"
 #include "base/time/time.h"
+#include "base/timer/timer.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/loader/cross_site_resource_handler.h"
 #include "content/browser/loader/resource_loader_delegate.h"
@@ -36,6 +38,8 @@ using base::TimeTicks;
 namespace content {
 namespace {
 
+const int kDefaultDetachableDelayOnCancelMs = 60000;
+
 void PopulateResourceResponse(net::URLRequest* request,
                               ResourceResponse* response) {
   response->head.error_code = request->status().error();
@@ -210,6 +214,7 @@ void ResourceLoader::Init(scoped_ptr<net::URLRequest> request,
   waiting_for_upload_progress_ack_ = false;
   is_transferring_ = false;
   client_cert_store_ = client_cert_store.Pass();
+  detachable_delay_on_cancel_ms_ = kDefaultDetachableDelayOnCancelMs;
 
   request_->set_delegate(this);
   handler_->SetController(this);
@@ -458,6 +463,16 @@ void ResourceLoader::StartRequestInternal() {
   delegate_->DidStartRequest(this);
 }
 
+void ResourceLoader::CancelAfterTimeout() {
+  if (detached_timer_)
+    return;
+
+  detached_timer_.reset(new base::OneShotTimer<ResourceLoader>());
+  detached_timer_->Start(
+      FROM_HERE, TimeDelta::FromMilliseconds(detachable_delay_on_cancel_ms_),
+      this, &ResourceLoader::Cancel);
+}
+
 void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
   VLOG(1) << "CancelRequestInternal: " << request_->url().spec();
 
@@ -469,6 +484,11 @@ void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
   if (from_renderer && (info->is_download() || info->is_stream()))
     return;
 
+  if (from_renderer && info->is_detachable()) {
+    CancelAfterTimeout();
+    return;
+  }
+
   // TODO(darin): Perhaps we should really be looking to see if the status is
   // IO_PENDING?
   bool was_pending = request_->is_pending();