Handle main resource preload request better

Source/core/fetch/ResourceFetcher.cpp

Index: Source/core/fetch/ResourceFetcher.cpp
diff --git a/Source/core/fetch/ResourceFetcher.cpp b/Source/core/fetch/ResourceFetcher.cpp
index f92a1d343172d46cdbbddd5226f0d742b20f7dfe..f9aaea5f86d191b02f4ba1b7b6a55820f95ffbc2 100644
--- a/Source/core/fetch/ResourceFetcher.cpp
+++ b/Source/core/fetch/ResourceFetcher.cpp
@@ -674,6 +674,11 @@ ResourcePtr<Resource> ResourceFetcher::requestResource(Resource::Type type, Fetc
 {
     ASSERT(request.options().synchronousPolicy == RequestAsynchronously || type == Resource::Raw);
 
+    // If loading main resource ensure main resources aren't preloaded.
+    if (type == Resource::MainResource && request.forPreload()) {

[Nate Chapin, 2014/06/06 23:00:01]

Ok. What if we move both this and the old code block to fetchMainResource()?
That address my organizational complaint, and avoids spinning up a
ResourceLoader unnecessarily.

+        return 0;
+    }
+
     TRACE_EVENT0("webkit", "ResourceFetcher::requestResource");
 
     KURL url = request.resourceRequest().url();
@@ -756,14 +761,11 @@ ResourcePtr<Resource> ResourceFetcher::requestResource(Resource::Type type, Fetc
     // resources, we should be sure to understand the implications for memory
     // use.
     //
-    // Ensure main resources aren't preloaded, and other main resource loads
-    // are removed from cache to prevent reuse.
+    // Main resource loads are removed from cache to prevent reuse.
     if (type == Resource::MainResource) {
         ASSERT(policy != Use || m_documentLoader->substituteData().isValid());
         ASSERT(policy != Revalidate);
         memoryCache()->remove(resource.get());
-        if (request.forPreload())
-            return 0;
     }
 
     requestLoadStarted(resource.get(), request, policy == Use ? ResourceLoadingFromCache : ResourceLoadingFromNetwork);