M1456: Implement MIME Sniffing

components/net/data_loader.rs

@@ -93,7 +93,7 @@ fn assert_parse(url:          &'static str,
     use sniffer_task;
 
     let (start_chan, start_port) = comm::channel();
-    let sniffer_task = sniffer_task::new_sniffer_task();
+    let sniffer_task = sniffer_task::new_mock_sniffer_task();
     load(LoadData::new(Url::parse(url).unwrap(), start_chan), sniffer_task);
 
     let response = start_port.recv();

components/net/lib.rs

@@ -39,6 +39,7 @@ pub mod local_image_cache;
 pub mod resource_task;
 pub mod storage_task;
 mod sniffer_task;
+mod mime_classifier;
 
 /// An implementation of the [Fetch spec](http://fetch.spec.whatwg.org/)
 pub mod fetch {