Remove resource type-specific fetching logic from ResourceFetcher

Source/core/fetch/ImageResource.h

Index: Source/core/fetch/ImageResource.h
diff --git a/Source/core/fetch/ImageResource.h b/Source/core/fetch/ImageResource.h
index 905f9277f3d7dce2fb96684f0c4b7c714357c787..5e18efd1e16a02623f963b9c16df77237a56fa84 100644
--- a/Source/core/fetch/ImageResource.h
+++ b/Source/core/fetch/ImageResource.h
@@ -34,6 +34,7 @@
 namespace blink {
 
 class ImageResourceClient;
+class FetchRequest;
 class ResourceFetcher;
 class FloatSize;
 class Length;
@@ -48,7 +49,8 @@ class CORE_EXPORT ImageResource final : public Resource, public ImageObserver {
 public:
     typedef ImageResourceClient ClientType;
 
-    ImageResource(const ResourceRequest&);
+    static ResourcePtr<ImageResource> fetch(FetchRequest&, ResourceFetcher*);
+
     ImageResource(blink::Image*);
     // Exposed for testing
     ImageResource(const ResourceRequest&, blink::Image*);
@@ -118,6 +120,20 @@ protected:
     virtual void destroyDecodedDataIfPossible() override;
 
 private:
+    static void preCacheDataURIImage(const FetchRequest&, ResourceFetcher*);
+
+    class ImageResourceFactory : public ResourceFactory {
+    public:
+        ImageResourceFactory()
+            : ResourceFactory(Resource::Image) { }
+
+        Resource* create(const ResourceRequest& request, const String&) const override
+        {
+            return new ImageResource(request);
+        }
+    };
+    ImageResource(const ResourceRequest&);
+
     void clear();
 
     void setCustomAcceptHeader();