Add ReadableStream operations to use it from Fetch API

third_party/WebKit/Source/core/streams/ReadableStream.js

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 (function(global, binding, v8) {
   'use strict';
 
   const readableStreamController = v8.createPrivateSymbol('[[controller]]');
   const readableStreamQueue = v8.createPrivateSymbol('[[queue]]');
   const readableStreamQueueSize =
@@ skipping 469 matching lines @@
   }
 
   function IsReadableStream(x) {
     return hasOwnProperty(x, readableStreamUnderlyingSource);
   }
 
   function IsReadableStreamDisturbed(stream) {
     return stream[readableStreamBits] & DISTURBED;
   }
 
+  function SetReadableStreamDisturbed(stream) {
+    return stream[readableStreamBits] |= DISTURBED;
+  }
+
   function IsReadableStreamLocked(stream) {
     return stream[readableStreamReader] !== undefined;
   }
 
   function IsReadableStreamController(x) {
     return hasOwnProperty(x, readableStreamControllerControlledReadableStream);
   }
 
+  function IsReadableStreamReadable(stream) {
+    return stream[readableStreamState] === STATE_READABLE;
+  }
+
+  function IsReadableStreamClosed(stream) {
+    return stream[readableStreamState] === STATE_CLOSED;
+  }
+
+  function IsReadableStreamErrored(stream) {
+    return stream[readableStreamState] === STATE_ERRORED;
+  }
+
   function IsReadableStreamReader(x) {
     return hasOwnProperty(x, readableStreamReaderOwnerReadableStream);
   }
 
   function ReadFromReadableStreamReader(reader) {
     const stream = reader[readableStreamReaderOwnerReadableStream];
     stream[readableStreamBits] |= DISTURBED;
 
     if (stream[readableStreamState] === STATE_CLOSED) {
       return Promise_resolve(CreateIterResultObject(undefined, true));
@@ skipping 269 matching lines @@
     writable: true
   });
 
   //
   // Exports to Blink
   //
 
   binding.AcquireReadableStreamReader = AcquireReadableStreamReader;
   binding.IsReadableStream = IsReadableStream;
   binding.IsReadableStreamDisturbed = IsReadableStreamDisturbed;
+  binding.SetReadableStreamDisturbed = SetReadableStreamDisturbed;
   binding.IsReadableStreamLocked = IsReadableStreamLocked;
+  binding.IsReadableStreamReadable = IsReadableStreamReadable;
+  binding.IsReadableStreamClosed = IsReadableStreamClosed;
+  binding.IsReadableStreamErrored = IsReadableStreamErrored;
   binding.IsReadableStreamReader = IsReadableStreamReader;
   binding.ReadFromReadableStreamReader = ReadFromReadableStreamReader;
 
   binding.CloseReadableStream = CloseReadableStream;
   binding.GetReadableStreamDesiredSize = GetReadableStreamDesiredSize;
   binding.EnqueueInReadableStream = EnqueueInReadableStream;
   binding.ErrorReadableStream = ErrorReadableStream;
 
   binding.createReadableStreamWithExternalController =
       (underlyingSource, strategy) => {
         return new ReadableStream(
             underlyingSource, strategy, createWithExternalControllerSentinel);
       };
 });