Add ReadableStream operations to use it from Fetch API

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

Index: third_party/WebKit/Source/core/streams/ReadableStream.js
diff --git a/third_party/WebKit/Source/core/streams/ReadableStream.js b/third_party/WebKit/Source/core/streams/ReadableStream.js
index 62522533c4b53b72374074307140a6d3230b6f9f..414c92343120fd65d3d7f87f4c38c6ffede89c77 100644
--- a/third_party/WebKit/Source/core/streams/ReadableStream.js
+++ b/third_party/WebKit/Source/core/streams/ReadableStream.js
@@ -487,6 +487,10 @@
     return stream[readableStreamBits] & DISTURBED;
   }
 
+  function SetReadableStreamDisturbed(stream) {
+    return stream[readableStreamBits] |= DISTURBED;
+  }
+
   function IsReadableStreamLocked(stream) {
     return stream[readableStreamReader] !== undefined;
   }
@@ -495,6 +499,18 @@
     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);
   }
@@ -784,7 +800,11 @@
   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;