Revert "fixup! short circuit with toWeb"

This reverts commit 06d670f.

lib/internal/streams/readable.js

@@ -34,7 +34,6 @@ const {
   SymbolAsyncDispose,
   SymbolAsyncIterator,
   Symbol,
-  SymbolFor,
 } = primordials;
 
 module.exports = Readable;
@@ -75,12 +74,6 @@ const { validateObject } = require('internal/validators');
 
 const kPaused = Symbol('kPaused');
 
-// This symbol is used to allow interop with ReadableStream
-// to allow checking for prototype pollution in the
-// async iterator to allow for using the toWeb functionality
-// in ReadableStream.from() implementation.
-const originalAsyncIteratorPrototype = SymbolFor('nodejs.stream.originalAsyncIteratorPrototype');
-
 const { StringDecoder } = require('string_decoder');
 const from = require('internal/streams/from');
 
@@ -1101,12 +1094,9 @@ Readable.prototype.wrap = function(stream) {
   return this;
 };
 
-function asyncIteratorPrototype() {
+Readable.prototype[SymbolAsyncIterator] = function() {
   return streamToAsyncIterator(this);
-}
-
-Readable.prototype[SymbolAsyncIterator] = asyncIteratorPrototype;
-Readable.prototype[originalAsyncIteratorPrototype] = asyncIteratorPrototype;
+};
 
 Readable.prototype.iterator = function(options) {
   if (options !== undefined) {

lib/internal/webstreams/readablestream.js

@@ -23,7 +23,6 @@ const {
   Symbol,
   SymbolAsyncIterator,
   SymbolToStringTag,
-  SymbolFor,
   Uint8Array,
 } = primordials;
 
@@ -83,7 +82,6 @@ const {
   kIsReadable,
   kIsClosedPromise,
   kControllerErrorFunction,
-  isReadableNodeStream,
 } = require('internal/streams/utils');
 
 const {
@@ -141,18 +139,9 @@ const kChunk = Symbol('kChunk');
 const kError = Symbol('kError');
 const kPull = Symbol('kPull');
 const kRelease = Symbol('kRelease');
-const kReadableOriginalAsyncIteratorPrototype = SymbolFor('nodejs.stream.originalAsyncIteratorPrototype');
 
 let releasedError;
 let releasingError;
-let readableStreamAdapters;
-
-function lazyReadableStreamAdapters() {
-  if (!readableStreamAdapters) {
-    readableStreamAdapters = require('internal/webstreams/adapters');
-  }
-  return readableStreamAdapters;
-}
 
 const userModuleRegExp = /^ {4}at (?:[^/\\(]+ \()(?!node:(.+):\d+:\d+\)$).*/gm;
 
@@ -1266,17 +1255,6 @@ const isReadableStreamBYOBReader =
 // ---- ReadableStream Implementation
 
 function readableStreamFromIterable(iterable) {
-  const strategy = {
-    size() {
-      return 1;
-    },
-    highWaterMark: 0,
-  };
-  if (isReadableNodeStream(iterable) &&
-  iterable[kReadableOriginalAsyncIteratorPrototype] === iterable[SymbolAsyncIterator]) {
-    return lazyReadableStreamAdapters().newReadableStreamFromStreamReadable(iterable, strategy);
-  }
-
   let stream;
   const iteratorRecord = getIterator(iterable, 'async');
 
@@ -1319,7 +1297,12 @@ function readableStreamFromIterable(iterable) {
     start: startAlgorithm,
     pull: pullAlgorithm,
     cancel: cancelAlgorithm,
-  }, strategy);
+  }, {
+    size() {
+      return 1;
+    },
+    highWaterMark: 0,
+  });
 
   return stream;
 }