Fix ReadableStream getReader({mode: 'byob'})

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 efac76a889537de85632d6713cd1642caaf30c68..a03e652fd95fc65b51f5f235b9c7ceaf387cf680 100644
--- a/third_party/WebKit/Source/core/streams/ReadableStream.js
+++ b/third_party/WebKit/Source/core/streams/ReadableStream.js
@@ -172,11 +172,13 @@
       }
 
       if (mode === 'byob') {
-        if (IsReadableByteStreamDefaultController(this[readableStreamController]) === false) {
-          throw new TypeError(errGetReaderNotByteStream);
-        }
-
-        return AcquireReadableStreamBYOBReader(this);
+        // TODO(ricea): When BYOB readers are supported:
+        //
+        // a. If
+        // ! IsReadableByteStreamController(this.[[readableStreamController]])
+        // is false, throw a TypeError exception.
+        // b. Return ? AcquireReadableStreamBYOBReader(this).
+        throw new TypeError(errGetReaderNotByteStream);
       }
 
       if (mode === undefined) {