Make ResourceLoadPriority calculation simpler

third_party/WebKit/Source/core/loader/LinkLoader.cpp

Index: third_party/WebKit/Source/core/loader/LinkLoader.cpp
diff --git a/third_party/WebKit/Source/core/loader/LinkLoader.cpp b/third_party/WebKit/Source/core/loader/LinkLoader.cpp
index fb6549e54502baa420190857417aa49970623f6a..f563594fe16ac0f7c60b651ff49c5beb7ca29792 100644
--- a/third_party/WebKit/Source/core/loader/LinkLoader.cpp
+++ b/third_party/WebKit/Source/core/loader/LinkLoader.cpp
@@ -297,7 +297,8 @@ static Resource* preloadIfNeeded(const LinkRelAttribute& relAttribute, const KUR
         document.addConsoleMessage(ConsoleMessage::create(OtherMessageSource, DebugMessageLevel, String("Preload triggered for " + href.host() + href.path())));
     linkRequest.setForPreload(true, monotonicallyIncreasingTime());
     linkRequest.setLinkPreload(true);
-    linkRequest.setPriority(document.fetcher()->loadPriority(resourceType, linkRequest));
+    if (resourceType == Resource::LinkPreload)
+        linkRequest.setDefer(FetchRequest::LazyLoad);

[Yoav Weiss, 2016/06/30 09:09:14]

I think you left that one out, as we said LinkPreload shouldn't be LazyLoad.
Also - how are tests passing with this change? :|

In general, I'll try to see if we can remove LinkPreload as a type entirely (and
just set it to whatever XHR is).

Also, I'm assuming that you deleted the `setPriority()` as it's no longer
needed, since priority is now set on the resource. Is that correct?

[Nate Chapin, 2016/07/20 19:05:03]

The tests currently expect LinkPreloads to be priority Low, instead of the usual
priority High for XHRs and other Raw resources. ResourceFetcher now
special-cases Raw LazyLoads to get that behavior. If you'd like me to change
what the tests expect instead, I'm happy to do that, but I was aiming to keep
this cleanup-only.
I *think* this priority difference is the only behavioral difference between the
LinkPreload and Raw types, so it should be straightforward?
s/resource/request/, but otherwise correct. The priority should now only be set
directly on the ResourceRequest, by FetchRequest::makeSynchrnous() for sync
requests, and by ResourceFetcher for all other cases.

     return document.loader()->startPreload(resourceType, linkRequest);
 }