Add methods for creating V8 extras-based ReadableStreams from C++

third_party/WebKit/Source/bindings/core/v8/ReadableStreamOperations.h

 // 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.
 
 #ifndef ReadableStreamOperations_h
 #define ReadableStreamOperations_h
 
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptValue.h"
 #include <v8.h>
 
 namespace blink {
 
+class UnderlyingSourceBase;
 class ExceptionState;
 class ScriptState;
 
 // This class has various methods for ReadableStream[Reader] implemented with
 // V8 Extras.
 // All methods should be called in an appropriate V8 context. All ScriptValue
 // arguments must not be empty.
 class CORE_EXPORT ReadableStreamOperations {
     STATIC_ONLY(ReadableStreamOperations);
 public:
+    // createReadableStreamWithExternalController
+    // If the caller supplies an invalid strategy (e.g. one that returns
+    // negative sizes, or doesn't have appropriate properties), this will crash.
+    static ScriptValue createReadableStream(ScriptState*, UnderlyingSourceBase*, ScriptValue strategy);
+
+    // createBuiltInCountQueuingStrategy
+    static ScriptValue createCountQueuingStrategy(ScriptState*, size_t highWaterMark);
+
     // AcquireReadableStreamReader
     // This function assumes |isReadableStream(stream)|.
     // Returns an empty value and throws an error via the ExceptionState when
     // errored.
     static ScriptValue getReader(ScriptState*, ScriptValue stream, ExceptionState&);
 
     // IsReadableStream
     static bool isReadableStream(ScriptState*, ScriptValue);
 
     // IsReadableStreamDisturbed
     // This function assumes |isReadableStream(stream)|.
     static bool isDisturbed(ScriptState*, ScriptValue stream);
 
     // IsReadableStreamLocked
     // This function assumes |isReadableStream(stream)|.
     static bool isLocked(ScriptState*, ScriptValue stream);
 
     // IsReadableStreamReader
     static bool isReadableStreamReader(ScriptState*, ScriptValue);
 
     // ReadFromReadableStreamReader
     // This function assumes |isReadableStreamReader(reader)|.
     static ScriptPromise read(ScriptState*, ScriptValue reader);
 };
 
 } // namespace blink
 
 #endif // ReadableStreamOperations_h