Introduce a new ResourceRequesterInfo type for NavigationPreload.

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 d70afa71e4951628f7a50d32a6a40b7f70dcaad2..9e3760be55c0ac1969cf04e75b78cefe23638d51 100644
--- a/content/browser/loader/resource_dispatcher_host_impl.cc
+++ b/content/browser/loader/resource_dispatcher_host_impl.cc
@@ -1067,7 +1067,7 @@ void ResourceDispatcherHostImpl::OnRequestResourceInternal(
     const ResourceRequest& request_data,
     mojom::URLLoaderAssociatedRequest mojo_request,
     mojom::URLLoaderClientAssociatedPtr url_loader_client) {
-  DCHECK(requester_info->IsRenderer());
+  DCHECK(requester_info->IsRenderer() || requester_info->IsNavigationPreload());
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/477117 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ -1273,11 +1273,12 @@ void ResourceDispatcherHostImpl::BeginRequest(
     int route_id,
     mojom::URLLoaderAssociatedRequest mojo_request,
     mojom::URLLoaderClientAssociatedPtr url_loader_client) {
-  DCHECK(requester_info->IsRenderer());
+  DCHECK(requester_info->IsRenderer() || requester_info->IsNavigationPreload());
   int child_id = requester_info->child_id();
 
   // Reject request id that's currently in use.
   if (IsRequestIDInUse(GlobalRequestID(child_id, request_id))) {
+    DCHECK(requester_info->IsRenderer());

[mmenke, 2016/12/01 15:26:11]

Think this is worth an explanation (Preloads have child_id's of -1 and
monotonically increasing request IDs allocated by MakeRequestID).

[horo, 2016/12/02 03:41:52]

Done.

     bad_message::ReceivedBadMessage(requester_info->filter(),
                                     bad_message::RDH_INVALID_REQUEST_ID);
     return;
@@ -1289,6 +1290,7 @@ void ResourceDispatcherHostImpl::BeginRequest(
       IsResourceTypeFrame(request_data.resource_type);
   if (is_navigation_stream_request &&
       !request_data.resource_body_stream_url.SchemeIs(url::kBlobScheme)) {
+    DCHECK(requester_info->IsRenderer());

[mmenke, 2016/12/01 15:26:11]

Explanation?  This isn't obvious.

[horo, 2016/12/02 03:41:52]

Done.

     bad_message::ReceivedBadMessage(requester_info->filter(),
                                     bad_message::RDH_INVALID_URL);
     return;
@@ -1297,6 +1299,7 @@ void ResourceDispatcherHostImpl::BeginRequest(
   // Reject invalid priority.
   if (request_data.priority < net::MINIMUM_PRIORITY ||
       request_data.priority > net::MAXIMUM_PRIORITY) {
+    DCHECK(requester_info->IsRenderer());
     bad_message::ReceivedBadMessage(requester_info->filter(),
                                     bad_message::RDH_INVALID_PRIORITY);
     return;
@@ -1378,8 +1381,9 @@ void ResourceDispatcherHostImpl::ContinuePendingBeginRequest(
     mojom::URLLoaderClientAssociatedPtr url_loader_client,
     bool continue_request,
     int error_code) {
-  DCHECK(requester_info->IsRenderer());
+  DCHECK(requester_info->IsRenderer() || requester_info->IsNavigationPreload());
   if (!continue_request) {
+    DCHECK(requester_info->IsRenderer());

[mmenke, 2016/12/01 15:26:11]

I don't think this is right?  We call out to "registered interceptor for the
headers passed in", and let them choose to cancel a request.  I don't see why
they could cancel non-renderer requests.

[mmenke, 2016/12/01 15:26:51]

Why they couldn't, rather

[horo, 2016/12/02 03:41:52]

Ah, yes. This could be a navigation preload request.
Changed to check "if (requester_info->IsRenderer())" and added tests.

     // TODO(ananta): Find a way to specify the right error code here.  Passing
     // in a non-content error code is not safe.
     bad_message::ReceivedBadMessage(requester_info->filter(),
@@ -1613,7 +1617,7 @@ ResourceDispatcherHostImpl::CreateResourceHandler(
     ResourceContext* resource_context,
     mojom::URLLoaderAssociatedRequest mojo_request,
     mojom::URLLoaderClientAssociatedPtr url_loader_client) {
-  DCHECK(requester_info->IsRenderer());
+  DCHECK(requester_info->IsRenderer() || requester_info->IsNavigationPreload());
   // TODO(pkasting): Remove ScopedTracker below once crbug.com/456331 is fixed.
   tracked_objects::ScopedTracker tracking_profile(
       FROM_HERE_WITH_EXPLICIT_FUNCTION(
@@ -1623,6 +1627,7 @@ ResourceDispatcherHostImpl::CreateResourceHandler(
   if (sync_result_handler) {
     // download_to_file is not supported for synchronous requests.
     if (request_data.download_to_file) {
+      DCHECK(requester_info->IsRenderer());
       bad_message::ReceivedBadMessage(requester_info->filter(),
                                       bad_message::RDH_BAD_DOWNLOAD);
       return std::unique_ptr<ResourceHandler>();