Remove references into sky/engine/core/fetch

sky/engine/core/core.gni

Index: sky/engine/core/core.gni
diff --git a/sky/engine/core/core.gni b/sky/engine/core/core.gni
index 44c18dcd7279752d9cc881a7efa52c4e46f69806..63b4bcf0714e2bf1a294c30e7b5e3fac59306001 100644
--- a/sky/engine/core/core.gni
+++ b/sky/engine/core/core.gni
@@ -297,8 +297,6 @@ sky_core_files = [
   "css/resolver/StyleResolverState.h",
   "css/resolver/StyleResolverStats.cpp",
   "css/resolver/StyleResolverStats.h",
-  "css/resolver/StyleResourceLoader.cpp",
-  "css/resolver/StyleResourceLoader.h",
   "css/resolver/TransformBuilder.cpp",
   "css/resolver/TransformBuilder.h",
   "dom/ActiveDOMObject.cpp",
@@ -707,17 +705,11 @@ sky_core_files = [
   "loader/DocumentLoadTiming.h",
   "loader/EmptyClients.cpp",
   "loader/EmptyClients.h",
-  "loader/FrameFetchContext.cpp",
-  "loader/FrameFetchContext.h",
   "loader/FrameLoader.cpp",
   "loader/FrameLoader.h",
   "loader/FrameLoaderClient.h",
   "loader/FrameLoaderTypes.h",
   "loader/ImageDecoderCallback.h",
-  "loader/ImageLoader.cpp",
-  "loader/ImageLoader.h",
-  "loader/MojoLoader.cpp",
-  "loader/MojoLoader.h",
   "loader/NavigationPolicy.h",
   "loader/UniqueIdentifier.cpp",
   "loader/UniqueIdentifier.h",