Implement OffscreenCanvas Accelerated 2D commit()

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 35 matching lines @@
 
 void OffscreenCanvasRenderingContext2D::commit(ExceptionState& exceptionState)
 {
     if (getOffscreenCanvas()->getAssociatedCanvasId() < 0) {
         // If an OffscreenCanvas has no associated canvas Id, it indicates that
         // it is not an OffscreenCanvas created by transfering control from html
         // canvas.
         exceptionState.throwDOMException(InvalidStateError, "Commit() was called on a context whose OffscreenCanvas is not associated with a canvas element.");
         return;
     }
-    getOffscreenCanvas()->getOrCreateFrameDispatcher()->dispatchFrame(nullptr);
+    RefPtr<StaticBitmapImage> image = this->transferToStaticBitmapImage();
+    DCHECK(image->isTextureBacked() == this->isAccelerated());

[Justin Novosad, 2016/09/22 19:27:39]

Why this DCHECK?  If for some reason this ever becomes false in the future (an
accelerated context produces a non-accelerated snapshot, for example), it should
not be a problem.

[xlai (Olivia), 2016/09/22 19:36:18]

Done.

+    getOffscreenCanvas()->getOrCreateFrameDispatcher()->dispatchFrame(image.release());
 }
 
 // BaseRenderingContext2D implementation
 bool OffscreenCanvasRenderingContext2D::originClean() const
 {
     return getOffscreenCanvas()->originClean();
 }
 
 void OffscreenCanvasRenderingContext2D::setOriginTainted()
 {
@@ skipping 50 matching lines @@
 
         if (m_needsMatrixClipRestore) {
             restoreMatrixClipStack(m_imageBuffer->canvas());
             nonConstThis->m_needsMatrixClipRestore = false;
         }
     }
 
     return m_imageBuffer.get();
 }
 
-ImageBitmap* OffscreenCanvasRenderingContext2D::transferToImageBitmap(ExceptionState& exceptionState)
+bool OffscreenCanvasRenderingContext2D::isAccelerated() const
+{
+    if (!hasImageBuffer())
+        return false;
+    return m_imageBuffer->isAccelerated();
+}
+
+PassRefPtr<StaticBitmapImage> OffscreenCanvasRenderingContext2D::transferToStaticBitmapImage()
 {
     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.release();
+}
+
+ImageBitmap* OffscreenCanvasRenderingContext2D::transferToImageBitmap(ExceptionState& exceptionState)
+{
+    RefPtr<StaticBitmapImage> image = transferToStaticBitmapImage();
+    if (!image)
+        return nullptr;
     m_imageBuffer.reset(); // "Transfer" means no retained buffer
     m_needsMatrixClipRestore = true;
     return ImageBitmap::create(image.release());
 }
 
 PassRefPtr<Image> OffscreenCanvasRenderingContext2D::getImage(AccelerationHint hint, SnapshotReason reason) const
 {
     if (!imageBuffer())
         return nullptr;
     sk_sp<SkImage> skImage = m_imageBuffer->newSkImageSnapshot(hint, reason);
@@ skipping 66 matching lines @@
 bool OffscreenCanvasRenderingContext2D::isContextLost() const
 {
     return false;
 }
 
 bool OffscreenCanvasRenderingContext2D::isPaintable() const
 {
     return this->imageBuffer();
 }
 }