Auto merge of #22133 - servo:extern-crate, r=SimonSapin

Use 2018-edition idioms in crates that use that edition

The first commit is almost entirely mechanical, created by running `cargo fix --edition-idioms` and relevant crates. I undid the change of adding an anonymous lifetime parameter in types that have implicit lifetimes parameters, for example replacing `&mut Formatter` with `&mut Formatter<'_>`, because I don’t like it. The remaining changes are, in many places:

* Add `dyn` to trait object types, for example `Rc<gl::Gl>` to `Rc<dyn gl::Gl>`. This change also works in the 2015 edition.
* Remove `extern crate` where is it made unneeded by changes to the import/module system.

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1 files changed, 1 insertions, 4 deletions

diff --git a/components/net/http_loader.rs b/components/net/http_loader.rs
index 8898fdf1924..ab1de55a1c9 100644
--- a/components/net/http_loader.rs
+++ b/components/net/http_loader.rs
@@ -36,8 +36,6 @@ use http::uri::Authority;
 use http::{HeaderMap, Request as HyperRequest};
 use hyper::{Body, Client, Method, Response as HyperResponse, StatusCode};
 use hyper_serde::Serde;
-use log;
-use mime;
 use msg::constellation_msg::{HistoryStateId, PipelineId};
 use net_traits::quality::{quality_to_value, Quality, QualityItem};
 use net_traits::request::{CacheMode, CredentialsMode, Destination, Origin};
@@ -61,7 +59,6 @@ use std::time::{Duration, SystemTime};
 use time::{self, Tm};
 use tokio::prelude::{future, Future, Stream};
 use tokio::runtime::Runtime;
-use uuid;
 
 lazy_static! {
     pub static ref HANDLE: Mutex<Runtime> = { Mutex::new(Runtime::new().unwrap()) };
@@ -380,7 +377,7 @@ fn obtain_response(
     request_id: Option<&str>,
     is_xhr: bool,
 ) -> Box<
-    Future<
+    dyn Future<
         Item = (
             HyperResponse<WrappedBody>,
             Option<ChromeToDevtoolsControlMsg>,