Pass a URI to package:http API (flutter#5202)

* Pass a URI to package:http API

Updates example to be forwards compatible with the breaking change in
dart-lang/http#507

* Other usages. Drop local variable type to match other example

Author: natebosch

src/docs/cookbook/networking/fetch-data.md

@@ -59,7 +59,7 @@ This recipe covers how to fetch a sample album from the
 <!-- skip -->
 ```dart
 Future<http.Response> fetchAlbum() {
-  return http.get('https://jsonplaceholder.typicode.com/albums/1');
+  return http.get(Uri.https('jsonplaceholder.typicode.com','albums/1'));
 }
 ```
 
@@ -242,7 +242,7 @@ import 'package:http/http.dart' as http;
 
 Future<Album> fetchAlbum() async {
   final response =
-      await http.get('https://jsonplaceholder.typicode.com/albums/1');
+      await http.get(Uri.https('jsonplaceholder.typicode.com', 'albums/1');
 
   if (response.statusCode == 200) {
     // If the server did return a 200 OK response,

src/docs/cookbook/networking/send-data.md

@@ -56,7 +56,7 @@ by sending an album title to the
 ```dart
 Future<http.Response> createAlbum(String title) {
   return http.post(
-    'https://jsonplaceholder.typicode.com/albums',
+    Uri.https('jsonplaceholder.typicode.com','albums'),
     headers: <String, String>{
       'Content-Type': 'application/json; charset=UTF-8',
     },
@@ -132,8 +132,8 @@ function to return a `Future<Album>`:
 <!-- skip -->
 ```dart
 Future<Album> createAlbum(String title) async {
-  final http.Response response = await http.post(
-    'https://jsonplaceholder.typicode.com/albums',
+  final response = await http.post(
+    Uri.https('jsonplaceholder.typicode.com','albums'),
     headers: <String, String>{
       'Content-Type': 'application/json; charset=UTF-8',
     },
@@ -242,8 +242,8 @@ import 'package:flutter/material.dart';
 import 'package:http/http.dart' as http;
 
 Future<Album> createAlbum(String title) async {
-  final http.Response response = await http.post(
-    'https://jsonplaceholder.typicode.com/albums',
+  final response = await http.post(
+    Uri.https('jsonplaceholder.typicode.com','albums'),
     headers: <String, String>{
       'Content-Type': 'application/json; charset=UTF-8',
     },