Allows prefetch requests to live beyond the renderer by delaying

content/browser/loader/async_resource_handler.cc

Index: content/browser/loader/async_resource_handler.cc
diff --git a/content/browser/loader/async_resource_handler.cc b/content/browser/loader/async_resource_handler.cc
index f007a417fb8ffe997e20c439506d9f8a6834c367..f1f8278297ca84faa1c5c39dd8fba6cc129f7d57 100644
--- a/content/browser/loader/async_resource_handler.cc
+++ b/content/browser/loader/async_resource_handler.cc
@@ -137,8 +137,9 @@ bool AsyncResourceHandler::OnUploadProgress(int request_id,
                                             uint64 size) {
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  // Cancel the request if the renderer is gone unless it's detachable.
   if (!info->filter())
-    return false;
+    return info->is_detachable();
   return info->filter()->Send(
       new ResourceMsg_UploadProgress(request_id, position, size));
 }
@@ -149,8 +150,9 @@ bool AsyncResourceHandler::OnRequestRedirected(int request_id,
                                                bool* defer) {
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  // Cancel the request if the renderer is gone unless it's detachable.
   if (!info->filter())
-    return false;
+    return info->is_detachable();
 
   *defer = did_defer_ = true;
 
@@ -177,8 +179,9 @@ bool AsyncResourceHandler::OnResponseStarted(int request_id,
 
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  // Cancel the request if the renderer is gone unless it's detachable.
   if (!info->filter())
-    return false;
+    return info->is_detachable();
 
   if (rdh_->delegate()) {
     rdh_->delegate()->OnResponseStarted(
@@ -249,6 +252,11 @@ bool AsyncResourceHandler::OnReadCompleted(int request_id, int bytes_read,
 
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  // Don't send any data for detachable requests.

[James Simonsen, 2013/10/26 02:25:00]

On face value, this doesn't sound right. It seems like this should be for
_detached_ requests. Why don't you want to populate the MemoryCache?

[jkarlin2, 2013/10/28 19:25:41]

Done.  There is now a distinct "detached" state and the AsyncResourceHandler
acts normally for detachable resources until detached, at which point messages
are no longer sent.  This changed the unit tests a little bit.

+  if (info->is_detachable()) {
+    buffer_->RecycleLeastRecentlyAllocated();
+    return true;
+  }
   if (!info->filter())
     return false;
 
@@ -311,8 +319,9 @@ bool AsyncResourceHandler::OnResponseCompleted(
     const std::string& security_info) {
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  // Cancel the request if the renderer is gone unless it's detachable.
   if (!info->filter())
-    return false;
+    return info->is_detachable();
 
   // If we crash here, figure out what URL the renderer was requesting.
   // http://crbug.com/107692