Minor clean up in transferToImageBitmap API

third_party/WebKit/Source/modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.cpp

 // Copyright 2016 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.
 
 #include "modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h"
 
 #include "bindings/modules/v8/OffscreenCanvasRenderingContext2DOrWebGLRenderingContextOrWebGL2RenderingContext.h"
 #include "core/frame/ImageBitmap.h"
 #include "core/frame/Settings.h"
 #include "core/workers/WorkerGlobalScope.h"
@@ skipping 119 matching lines @@
   if (!imageBuffer())
     return nullptr;
   sk_sp<SkImage> skImage = m_imageBuffer->newSkImageSnapshot(
       PreferAcceleration, SnapshotReasonTransferToImageBitmap);
   RefPtr<StaticBitmapImage> image =
       StaticBitmapImage::create(std::move(skImage));
   image->setOriginClean(this->originClean());
   return image;
 }
 
-ImageBitmap* OffscreenCanvasRenderingContext2D::transferToImageBitmap(
-    ExceptionState& exceptionState) {
+ImageBitmap* OffscreenCanvasRenderingContext2D::transferToImageBitmap() {
   RefPtr<StaticBitmapImage> image = transferToStaticBitmapImage();
   if (!image)
     return nullptr;
   m_imageBuffer.reset();  // "Transfer" means no retained buffer
   m_needsMatrixClipRestore = true;
   return ImageBitmap::create(std::move(image));
 }
 
 PassRefPtr<Image> OffscreenCanvasRenderingContext2D::getImage(
     AccelerationHint hint,
@@ skipping 65 matching lines @@
 }
 
 bool OffscreenCanvasRenderingContext2D::isContextLost() const {
   return false;
 }
 
 bool OffscreenCanvasRenderingContext2D::isPaintable() const {
   return this->imageBuffer();
 }
 }