Re-land: Make 2D canvas smarter about chosing whether or not to use GPU acceleration

third_party/WebKit/Source/core/html/HTMLCanvasElement.cpp

 /*
  * Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 458 matching lines @@
         lowercaseMimeType = "image/png";
 
     return lowercaseMimeType;
 }
 
 const AtomicString HTMLCanvasElement::imageSourceURL() const
 {
     return AtomicString(toDataURLInternal("image/png", 0, FrontBuffer));
 }
 
+void HTMLCanvasElement::prepareSurfaceForPaintingIfNeeded() const
+{
+    ASSERT(m_context && m_context->is2d()); // This function is called by the 2d context
+    if (buffer())
+        m_imageBuffer->prepareSurfaceForPaintingIfNeeded();
+}
+
 ImageData* HTMLCanvasElement::toImageData(SourceDrawingBuffer sourceBuffer) const
 {
     ImageData* imageData;
     if (is3D()) {
         // Get non-premultiplied data because of inaccurate premultiplied alpha conversion of buffer()->toDataURL().
         imageData = m_context->paintRenderingResultsToImageData(sourceBuffer);
         if (imageData)
             return imageData;
 
         m_context->paintRenderingResultsToCanvas(sourceBuffer);
         imageData = ImageData::create(m_size);
-        RefPtr<SkImage> snapshot = buffer()->newSkImageSnapshot();
+        RefPtr<SkImage> snapshot = buffer()->newSkImageSnapshot(PreferNoAcceleration);
         if (snapshot) {
             SkImageInfo imageInfo = SkImageInfo::Make(width(), height(), kRGBA_8888_SkColorType, kUnpremul_SkAlphaType);
             snapshot->readPixels(imageInfo, imageData->data()->data(), imageInfo.minRowBytes(), 0, 0);
         }
         return imageData;
     }
 
     imageData = ImageData::create(m_size);
 
     if (!m_context)
         return imageData;
 
     ASSERT(m_context->is2d());
-    RefPtr<SkImage> snapshot = buffer()->newSkImageSnapshot();
+    RefPtr<SkImage> snapshot = buffer()->newSkImageSnapshot(PreferNoAcceleration);
     if (snapshot) {
         SkImageInfo imageInfo = SkImageInfo::Make(width(), height(), kRGBA_8888_SkColorType, kUnpremul_SkAlphaType);
         snapshot->readPixels(imageInfo, imageData->data()->data(), imageInfo.minRowBytes(), 0, 0);
     }
 
     return imageData;
 }
 
 String HTMLCanvasElement::toDataURLInternal(const String& mimeType, const double* quality, SourceDrawingBuffer sourceBuffer) const
 {
@@ skipping 150 matching lines @@
         // FIXME: Actually, avoid setting m_accelerationDisabled at all when
         // doing GPU-based rasterization.
         if (m_accelerationDisabled)
             return adoptPtr(new UnacceleratedImageBufferSurface(deviceSize, opacityMode));
         return adoptPtr(new AcceleratedImageBufferSurface(deviceSize, opacityMode));
     }
 
     if (shouldAccelerate(deviceSize)) {
         if (document().settings())
             *msaaSampleCount = document().settings()->accelerated2dCanvasMSAASampleCount();
-        OwnPtr<ImageBufferSurface> surface = adoptPtr(new Canvas2DImageBufferSurface(deviceSize, opacityMode, *msaaSampleCount));
+        OwnPtr<ImageBufferSurface> surface = adoptPtr(new Canvas2DImageBufferSurface(deviceSize, *msaaSampleCount, opacityMode, Canvas2DLayerBridge::EnableAcceleration));
         if (surface->isValid())
             return surface.release();
     }
 
     OwnPtr<RecordingImageBufferFallbackSurfaceFactory> surfaceFactory = adoptPtr(new UnacceleratedSurfaceFactory());
 
     if (shouldUseDisplayList(deviceSize)) {
         OwnPtr<ImageBufferSurface> surface = adoptPtr(new RecordingImageBufferSurface(deviceSize, surfaceFactory.release(), opacityMode));
         if (surface->isValid())
             return surface.release();
@@ skipping 143 matching lines @@
 {
     ASSERT(m_context);
     if ((hasImageBuffer() && !m_imageBuffer->isAccelerated()) || m_didFailToCreateImageBuffer)
         return;
     discardImageBuffer();
     OpacityMode opacityMode = m_context->hasAlpha() ? NonOpaque : Opaque;
     m_imageBuffer = ImageBuffer::create(size(), opacityMode);
     m_didFailToCreateImageBuffer = !m_imageBuffer;
 }
 
-PassRefPtr<Image> HTMLCanvasElement::copiedImage(SourceDrawingBuffer sourceBuffer) const
+PassRefPtr<Image> HTMLCanvasElement::copiedImage(SourceDrawingBuffer sourceBuffer, AccelerationHint hint) const
 {
     if (!isPaintable())
         return nullptr;
     if (!m_context)
         return createTransparentImage(size());
 
     bool needToUpdate = !m_copiedImage;
     // The concept of SourceDrawingBuffer is valid on only WebGL.
     if (m_context->is3d())
         needToUpdate |= m_context->paintRenderingResultsToCanvas(sourceBuffer);
     if (needToUpdate && buffer()) {
-        m_copiedImage = buffer()->newImageSnapshot();
+        m_copiedImage = buffer()->newImageSnapshot(hint);
         updateExternallyAllocatedMemory();
     }
     return m_copiedImage;
 }
 
 void HTMLCanvasElement::discardImageBuffer()
 {
     m_imageBuffer.clear();
     m_dirtyRect = FloatRect();
     updateExternallyAllocatedMemory();
@@ skipping 34 matching lines @@
 }
 
 void HTMLCanvasElement::didMoveToNewDocument(Document& oldDocument)
 {
     setObservedDocument(document());
     if (m_context)
         m_context->didMoveToNewDocument(&document());
     HTMLElement::didMoveToNewDocument(oldDocument);
 }
 
-PassRefPtr<Image> HTMLCanvasElement::getSourceImageForCanvas(SourceImageStatus* status) const
+PassRefPtr<Image> HTMLCanvasElement::getSourceImageForCanvas(SourceImageStatus* status, AccelerationHint hint) const
 {
     if (!width() || !height()) {
         *status = ZeroSizeCanvasSourceImageStatus;
         return nullptr;
     }
 
     if (!isPaintable()) {
         *status = InvalidSourceImageStatus;
         return nullptr;
     }
 
     if (!m_context) {
         *status = NormalSourceImageStatus;
         return createTransparentImage(size());
     }
 
     if (m_context->is3d()) {
         m_context->paintRenderingResultsToCanvas(BackBuffer);
     }
 
-    RefPtr<SkImage> image = buffer()->newSkImageSnapshot();
+    RefPtr<SkImage> image = buffer()->newSkImageSnapshot(hint);
     if (image) {
         *status = NormalSourceImageStatus;
         return StaticBitmapImage::create(image.release());
     }
 
     *status = InvalidSourceImageStatus;
     return nullptr;
 }
 
 bool HTMLCanvasElement::wouldTaintOrigin(SecurityOrigin*) const
 {
     return !originClean();
 }
 
 FloatSize HTMLCanvasElement::elementSize() const
 {
     return FloatSize(width(), height());
 }
 
 bool HTMLCanvasElement::isOpaque() const
 {
     return m_context && !m_context->hasAlpha();
 }
 
 } // blink