Make OffscreenCanvasRenderingContext2D renderable on a worker

third_party/WebKit/Source/modules/offscreencanvas/OffscreenCanvas.cpp

 // 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.
 
 #include "modules/offscreencanvas/OffscreenCanvas.h"
 
+#include "core/dom/ExceptionCode.h"
+#if !ENABLE(OILPAN)
+#include "core/frame/ImageBitmap.h" // So ~RefPtr can call unref()
+#endif
 #include "core/html/canvas/CanvasContextCreationAttributes.h"
 #include "modules/offscreencanvas/OffscreenCanvasRenderingContext.h"
 #include "modules/offscreencanvas/OffscreenCanvasRenderingContextFactory.h"
 #include "modules/offscreencanvas2d/OffscreenCanvasRenderingContext2D.h"
 #include "wtf/MathExtras.h"
 
 namespace blink {
 
+OffscreenCanvas::OffscreenCanvas(const IntSize& size)
+    : m_size(size)
+{ }
+
+OffscreenCanvas::~OffscreenCanvas()
+{ }
+
 OffscreenCanvas* OffscreenCanvas::create(unsigned width, unsigned height)
 {
     return new OffscreenCanvas(IntSize(clampTo<int>(width), clampTo<int>(height)));
 }
 
 void OffscreenCanvas::setWidth(unsigned width)
 {
     m_size.setWidth(clampTo<int>(width));
 }
 
 void OffscreenCanvas::setHeight(unsigned height)
 {
     m_size.setHeight(clampTo<int>(height));
 }
 
-OffscreenCanvas::OffscreenCanvas(const IntSize& size)
-    : m_size(size)
-{
-}
-
 OffscreenCanvasRenderingContext2D* OffscreenCanvas::getContext(const String& id, const CanvasContextCreationAttributes& attributes)
 {
     OffscreenCanvasRenderingContext::ContextType contextType = OffscreenCanvasRenderingContext::contextTypeFromId(id);
 
     // Unknown type.
     if (contextType == OffscreenCanvasRenderingContext::ContextTypeCount)
         return nullptr;
 
     OffscreenCanvasRenderingContextFactory* factory = getRenderingContextFactory(contextType);
     if (!factory)
         return nullptr;
 
     if (m_context) {
         if (m_context->getContextType() != contextType) {
             factory->onError(this, "OffscreenCanvas has an existing context of a different type");
             return nullptr;
         }
     } else {
         m_context = factory->create(this, attributes);
     }
 
     // TODO: When there're more than one context type implemented in the future,
     // the return type here should be changed to base class of all Offscreen
     // context types.
     return static_cast<OffscreenCanvasRenderingContext2D*>(m_context.get());
 }
 
+PassRefPtrWillBeRawPtr<ImageBitmap> OffscreenCanvas::transferToImageBitmap(ExceptionState& exceptionState)
+{
+    if (!m_context) {
+        exceptionState.throwDOMException(InvalidStateError, "Cannot transfer an ImageBitmap from an OffscreenCanvas with no context");
+        return nullptr;
+    }
+    RefPtrWillBeRawPtr<ImageBitmap> image = m_context->transferToImageBitmap(exceptionState);
+    if (!image) {
+        // Undocumented exception (not in spec)
+        exceptionState.throwDOMException(V8GeneralError, "Out of memory");
+    }
+    return image.release();
+}
+
 OffscreenCanvasRenderingContext2D* OffscreenCanvas::renderingContext() const
 {
     // TODO: When there're more than one context type implemented in the future,
     // the return type here should be changed to base class of all Offscreen
     // context types.
     return static_cast<OffscreenCanvasRenderingContext2D*>(m_context.get());
 }
 
 OffscreenCanvas::ContextFactoryVector& OffscreenCanvas::renderingContextFactories()
 {
@@ skipping 14 matching lines @@
     ASSERT(!renderingContextFactories()[type]);
     renderingContextFactories()[type] = renderingContextFactory;
 }
 
 DEFINE_TRACE(OffscreenCanvas)
 {
     visitor->trace(m_context);
 }
 
 } // namespace blink