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..4f196d9484ccaa9a6e2e5c98226a591569dddc7a 100644
--- a/content/browser/loader/async_resource_handler.cc
+++ b/content/browser/loader/async_resource_handler.cc
@@ -150,7 +150,7 @@ bool AsyncResourceHandler::OnRequestRedirected(int request_id,
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
   if (!info->filter())
-    return false;
+    return info->is_detachable();

[mmenke, 2013/10/17 18:33:48]

I think all of these need a comment along the lines of "If detachable, just
continue with the request.  Otherwise, cancel it."

[jkarlin2, 2013/10/24 15:33:11]

Done.

 
   *defer = did_defer_ = true;
 
@@ -178,7 +178,7 @@ bool AsyncResourceHandler::OnResponseStarted(int request_id,
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
   if (!info->filter())
-    return false;
+    return info->is_detachable();
 
   if (rdh_->delegate()) {
     rdh_->delegate()->OnResponseStarted(
@@ -249,6 +249,10 @@ bool AsyncResourceHandler::OnReadCompleted(int request_id, int bytes_read,
 
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
+  if (info->is_detachable()) {

[mmenke, 2013/10/17 18:33:48]

Again, comment that renderers don't care about reads from detachable requests
(Does devtools care?)

[jkarlin2, 2013/10/24 15:33:11]

Done.

+    buffer_->RecycleLeastRecentlyAllocated();
+    return true;
+  }
   if (!info->filter())
     return false;
 
@@ -312,7 +316,7 @@ bool AsyncResourceHandler::OnResponseCompleted(
   const ResourceRequestInfoImpl* info =
       ResourceRequestInfoImpl::ForRequest(request_);
   if (!info->filter())
-    return false;
+    return info->is_detachable();

[mmenke, 2013/10/17 18:33:48]

Hmm....Wonder about returning false in this case in the first place.

[jkarlin2, 2013/10/24 15:33:11]

Noted. It's unclear to me.  The loader seems to interpret false as a need to 
jump into a DEFERRED_FINISH state.  I want to change as little existing behavior
as possible in this CL though so will leave the same.

 
   // If we crash here, figure out what URL the renderer was requesting.
   // http://crbug.com/107692