Make OffscreenCanvas a member of CanvasImageSource

third_party/WebKit/Source/core/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 "core/offscreencanvas/OffscreenCanvas.h"
 
 #include "core/dom/ExceptionCode.h"
 #include "core/html/canvas/CanvasContextCreationAttributes.h"
 #include "core/html/canvas/CanvasRenderingContext.h"
 #include "core/html/canvas/CanvasRenderingContextFactory.h"
@@ skipping 43 matching lines @@
         return nullptr;
     }
     ImageBitmap* image = m_context->transferToImageBitmap(exceptionState);
     if (!image) {
         // Undocumented exception (not in spec)
         exceptionState.throwDOMException(V8Error, "Out of memory");
     }
     return image;
 }
 
+PassRefPtr<Image> OffscreenCanvas::getSourceImageForCanvas(SourceImageStatus* status, AccelerationHint, SnapshotReason reason, const FloatSize&) const
+{
+    if (!m_context) {
+        *status = InvalidSourceImageStatus;
+        return nullptr;
+    }
+    *status = NormalSourceImageStatus;
+    return m_context->getImage(reason);
+}
+
+bool OffscreenCanvas::isOpaque() const
+{
+    if (!m_context)
+        return false;
+    return !m_context->creationAttributes().hasAlpha();
+}
+
 CanvasRenderingContext* OffscreenCanvas::getCanvasRenderingContext(ScriptState* scriptState, const String& id, const CanvasContextCreationAttributes& attributes)
 {
     CanvasRenderingContext::ContextType contextType = CanvasRenderingContext::contextTypeFromId(id);
 
     // Unknown type.
     if (contextType == CanvasRenderingContext::ContextTypeCount)
         return nullptr;
 
     CanvasRenderingContextFactory* factory = getRenderingContextFactory(contextType);
     if (!factory)
@@ skipping 42 matching lines @@
         return ImageBuffer::canCreateImageBuffer(m_size);
     return m_context->isPaintable();
 }
 
 DEFINE_TRACE(OffscreenCanvas)
 {
     visitor->trace(m_context);
 }
 
 } // namespace blink