Add 'XHR' to the Resource::Type enum, and use it for XHR requests.

Source/core/fetch/ResourceFetcher.h

Index: Source/core/fetch/ResourceFetcher.h
diff --git a/Source/core/fetch/ResourceFetcher.h b/Source/core/fetch/ResourceFetcher.h
index 76f8990c5d7af4eb9994143ac1c63bb7e3b2e763..bdbf7eb181dc0bcea3d3d238072a943d22df6e46 100644
--- a/Source/core/fetch/ResourceFetcher.h
+++ b/Source/core/fetch/ResourceFetcher.h
@@ -91,6 +91,7 @@ public:
     ResourcePtr<ScriptResource> fetchScript(FetchRequest&);
     ResourcePtr<FontResource> fetchFont(FetchRequest&);
     ResourcePtr<RawResource> fetchRawResource(FetchRequest&);
+    ResourcePtr<RawResource> fetchXMLHttpRequest(FetchRequest&);
     ResourcePtr<RawResource> fetchMainResource(FetchRequest&, const SubstituteData&);
     ResourcePtr<DocumentResource> fetchSVGDocument(FetchRequest&);
     ResourcePtr<XSLStyleSheetResource> fetchXSLStyleSheet(FetchRequest&);
@@ -189,7 +190,7 @@ private:
     void addAdditionalRequestHeaders(ResourceRequest&, Resource::Type);
 
     bool canRequest(Resource::Type, const KURL&, const ResourceLoaderOptions&, bool forPreload, FetchRequest::OriginRestriction) const;
-    bool checkInsecureContent(Resource::Type, const KURL&, MixedContentBlockingTreatment) const;
+    bool checkInsecureContent(Resource::Type, const KURL&) const;
 
     static bool resourceNeedsLoad(Resource*, const FetchRequest&, RevalidationPolicy);