Add link preload as=document support

third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp

Index: third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
diff --git a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
index 5ff0d0d3861a31c60532f733a76016d704734229..e30dae72ff16cd976d11744b9cb552ff00e19ea6 100644
--- a/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
+++ b/third_party/WebKit/Source/core/fetch/ResourceFetcher.cpp
@@ -1024,7 +1024,7 @@ void ResourceFetcher::moveResourceLoaderToNonBlocking(ResourceLoader* loader)
 bool ResourceFetcher::startLoad(Resource* resource)
 {
     DCHECK(resource && resource->stillNeedsLoad());
-    if (!context().shouldLoadNewResource(resource->getType())) {
+    if (!context().shouldLoadNewResource(resource->getType(), resource->resourceRequest().frameType())) {
         memoryCache()->remove(resource);
         return false;
     }
@@ -1180,6 +1180,8 @@ void ResourceFetcher::logPreloadStats()
     unsigned importMisses = 0;
     unsigned raws = 0;
     unsigned rawMisses = 0;
+    unsigned mains = 0;
+    unsigned mainMisses = 0;
     for (auto resource : *m_preloads) {
         int missCount = resource->getPreloadResult() == Resource::PreloadNotReferenced ? 1 : 0;
         switch (resource->getType()) {
@@ -1215,6 +1217,10 @@ void ResourceFetcher::logPreloadStats()
             raws++;
             rawMisses += missCount;
             break;
+        case Resource::MainResource:
+            mains++;
+            mainMisses += missCount;
+            break;
         default:
             ASSERT_NOT_REACHED();
         }