ResourceScheduler: remove dependency on ResourceRequestInfo and request_id

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 5600a23455fc80f8f2a6592077a78be2babcb165..d6db79ffa1ea1f8ad52cdec6bd41b23b5d0c8c93 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -978,6 +978,7 @@ bool ResourceDispatcherHostImpl::OnMessageReceived(
     IPC_MESSAGE_HANDLER(ResourceHostMsg_DataDownloaded_ACK, OnDataDownloadedACK)
     IPC_MESSAGE_HANDLER(ResourceHostMsg_UploadProgress_ACK, OnUploadProgressACK)
     IPC_MESSAGE_HANDLER(ResourceHostMsg_CancelRequest, OnCancelRequest)
+    IPC_MESSAGE_HANDLER(ResourceHostMsg_DidChangePriority, OnDidChangePriority)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
 
@@ -1435,8 +1436,10 @@ scoped_ptr<ResourceHandler> ResourceDispatcherHostImpl::AddStandardHandlers(
     throttles.push_back(new PowerSaveBlockResourceThrottle());
   }
 
-  throttles.push_back(
-      scheduler_->ScheduleRequest(child_id, route_id, request).release());
+  // TODO(ricea): Stop looking this up so much.
+  ResourceRequestInfoImpl* info = ResourceRequestInfoImpl::ForRequest(request);
+  throttles.push_back(scheduler_->ScheduleRequest(child_id, route_id,
+                                                  info->IsAsync(), request));
 
   handler.reset(
       new ThrottlingResourceHandler(handler.Pass(), request, throttles.Pass()));
@@ -1448,6 +1451,26 @@ void ResourceDispatcherHostImpl::OnReleaseDownloadedFile(int request_id) {
   UnregisterDownloadedTempFile(filter_->child_id(), request_id);
 }
 
+void ResourceDispatcherHostImpl::OnDidChangePriority(
+    int request_id,
+    net::RequestPriority new_priority,
+    int intra_priority_value) {
+  ResourceLoader* loader = GetLoader(filter_->child_id(), request_id);
+  // The request may go away before processing this message, so |loader| can
+  // legitimately be null.
+  if (!loader)
+    return;
+  auto* scheduled_resource_request =
+      ResourceScheduler::ScheduledResourceRequest::ForRequest(
+          loader->request());
+  // Downloads don't use the resource scheduler.
+  // TODO(ricea): Can a DidChangePriority message for a download be legitimate?

[davidben, 2015/08/13 23:08:52]

There's two ways to get a download. One is if a normal navigation turns into one
post-commit. That doesn't happen until after OnResponseStarted, so I think the
ResourceScheduler is no longer relevant. And we lie to the renderer and tell it
the request failed.

Though... actually I bet it can still send these IPCs. Meh, I'll fix that as
part of the ResourceLoader cleanup to make it actually an ownership transfer.

The other way to get a download is via <a download> or Save Page As. Those don't
even get request IDs, so the renderer shouldn't send those IPCs.

Anyway, tl;dr: I think you can remove the TODO. :-)

[Adam Rice, 2015/08/13 23:42:28]

Done.

+  if (!scheduled_resource_request)
+    return;
+  scheduled_resource_request->ChangePriority(new_priority,
+                                             intra_priority_value);
+}
+
 void ResourceDispatcherHostImpl::OnDataDownloadedACK(int request_id) {
   // TODO(michaeln): maybe throttle DataDownloaded messages
 }