Remove net from dependencies

components/net_traits/fetch/headers.rs

@@ -0,0 +1,21 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at https://mozilla.org/MPL/2.0/. */
+
+use headers::HeaderMap;
+
+/// <https://fetch.spec.whatwg.org/#concept-header-list-get>
+pub fn get_value_from_header_list(name: &str, headers: &HeaderMap) -> Option<String> {
+    let values = headers
+        .get_all(name)
+        .iter()
+        .map(|val| val.to_str().unwrap());
+
+    // Step 1
+    if values.size_hint() == (0, Some(0)) {
+        return None;
+    }
+
+    // Step 2
+    return Some(values.collect::<Vec<&str>>().join(", "));
+}