Revert recent changes to File.openRead() and HttpClientResponse APIs

This changes `File.openRead()` back to returning a `Stream<List<int>>`
and `HttpClientResponse` back to implementing `Stream<List<int>>`.
These two changes broke a significant number of call sites; backing it
out enables us to keep the changes from landing in the next dev release
until we analyze whether we can roll these changes out in a softer
manner or if they're worth making at all.

Bug: https://github.com/dart-lang/sdk/issues/36900
Change-Id: I8977abcba40c58a4ca2b4a05d857512989a1e0b4
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/109102
Reviewed-by: Lasse R.H. Nielsen <lrn@google.com>
Commit-Queue: Todd Volkert <tvolkert@google.com>

CHANGELOG.md

@@ -22,12 +22,10 @@
   * `RawSocket.read()`
   * `Utf8Codec.encode()` (and `Utf8Encoder.convert()`)
 
-  In addition, the following methods and classes were updated to return or
-  implement `Stream<Uint8List>` rather than `Stream<List<int>>`:
+  In addition, the following classes were updated to implement
+  `Stream<Uint8List>` rather than `Stream<List<int>>`:
 
-  * `File.openRead()`
   * `HttpRequest`
-  * `HttpClientResponse`
   * `Socket`
 
   **Possible errors and how to fix them**

sdk/lib/_http/http.dart

@@ -1947,7 +1947,7 @@ abstract class HttpClientRequest implements IOSink {
  *            });
  *          });
  */
-abstract class HttpClientResponse implements Stream<Uint8List> {
+abstract class HttpClientResponse implements Stream<List<int>> {
   /**
    * Returns the status code.
    *

sdk/lib/_http/http_impl.dart

@@ -173,6 +173,23 @@ class _HttpIncoming extends Stream<Uint8List> {
   }
 }
 
+abstract class _HttpInboundMessageListInt extends Stream<List<int>> {
+  final _HttpIncoming _incoming;
+  List<Cookie> _cookies;
+
+  _HttpInboundMessageListInt(this._incoming);
+
+  List<Cookie> get cookies {
+    if (_cookies != null) return _cookies;
+    return _cookies = headers._parseCookies();
+  }
+
+  _HttpHeaders get headers => _incoming.headers;
+  String get protocolVersion => headers.protocolVersion;
+  int get contentLength => headers.contentLength;
+  bool get persistentConnection => headers.persistentConnection;
+}
+
 abstract class _HttpInboundMessage extends Stream<Uint8List> {
   final _HttpIncoming _incoming;
   List<Cookie> _cookies;
@@ -282,7 +299,7 @@ class _HttpRequest extends _HttpInboundMessage implements HttpRequest {
   }
 }
 
-class _HttpClientResponse extends _HttpInboundMessage
+class _HttpClientResponse extends _HttpInboundMessageListInt
     implements HttpClientResponse {
   List<RedirectInfo> get redirects => _httpRequest._responseRedirects;
 

sdk/lib/io/file.dart

@@ -483,7 +483,7 @@ abstract class File implements FileSystemEntity {
    * must be read to completion or the subscription on the stream must
    * be cancelled.
    */
-  Stream<Uint8List> openRead([int start, int end]);
+  Stream<List<int>> openRead([int start, int end]);
 
   /**
    * Creates a new independent [IOSink] for the file. The

sdk/lib/io/file_impl.dart

@@ -7,7 +7,7 @@ part of dart.io;
 // Read the file in blocks of size 64k.
 const int _blockSize = 64 * 1024;
 
-class _FileStream extends Stream<Uint8List> {
+class _FileStream extends Stream<List<int>> {
   // Stream controller.
   StreamController<Uint8List> _controller;
 
@@ -498,7 +498,7 @@ class _File extends FileSystemEntity implements File {
     return new _RandomAccessFile(id, "");
   }
 
-  Stream<Uint8List> openRead([int start, int end]) {
+  Stream<List<int>> openRead([int start, int end]) {
     return new _FileStream(path, start, end);
   }