ChangeLog

2020-07-22  Justin Fan  <justin_fan@apple.com>

        [WebGL] Safari snapshots of WebGL content in the tab picker don't work

        https://bugs.webkit.org/show_bug.cgi?id=214452

        <rdar://problem/21243082>

        Reviewed by NOBODY (OOPS!).

        No new tests; writing a test may involve adding a new feature to TestRunner to trigger this path.

        * html/HTMLCanvasElement.cpp:

        (WebCore::HTMLCanvasElement::paint): Will properly request a paint when a snapshot is requested.

        * html/HTMLCanvasElement.h:

        * html/canvas/WebGLRenderingContextBase.cpp:

        (WebCore::WebGLRenderingContextBase::paintRenderingResultsToCanvas): Only clear the last snapshot if readPixels will succeed.

        * rendering/RenderHTMLCanvas.cpp:

        (WebCore::RenderHTMLCanvas::paintReplaced):

2020-07-22  Fujii Hironori  <Hironori.Fujii@sony.com>

        [WinCairo][32bit] JPEG2000ImageDecoder.cpp: error C2664: 'std::unique_ptr<...>::unique_ptr(...)': cannot convert argument 2 from 'void (__stdcall *)(opj_codec_t *)' to 'const _Dx &'

Source/WebCore/html/HTMLCanvasElement.cpp

@@void HTMLCanvasElement::paint(GraphicsContext& context, const LayoutRect& r)

        bool shouldPaint = true;

        if (m_context) {

638 shouldPaint = paintsIntoCanvasBuffer() || document().printing();

638 shouldPaint = paintsIntoCanvasBuffer() || document().printing() || m_isSnapshotting;

            if (shouldPaint)

                m_context->paintRenderingResultsToCanvas();

        }

Source/WebCore/html/HTMLCanvasElement.h

@@public:

    bool needsPreparationForDisplay();

    void prepareForDisplay();

    void setIsSnapshotting(bool isSnapshotting) { m_isSnapshotting = isSnapshotting; }

    bool isSnapshotting() const { return m_isSnapshotting; }

private:

    HTMLCanvasElement(const QualifiedName&, Document&);

@@private:

    bool m_hasRelevantWebGLEventListener { false };

#endif

194 bool m_isSnapshotting { false };

195

    mutable RefPtr<Image> m_presentedImage;

    mutable RefPtr<Image> m_copiedImage; // FIXME: This is temporary for platforms that have to copy the image buffer to render (and for CSSCanvasValue).

};

Source/WebCore/html/canvas/WebGLRenderingContextBase.cpp

@@void WebGLRenderingContextBase::paintRenderingResultsToCanvas()

    if (!canvas)

        return;

1191 if (canvas->document().printing())

1191 if (canvas->document().printing() || (canvas->isSnapshotting() && canvas->document().page()->isVisible()))

        canvas->clearPresentationCopy();

    // Until the canvas is written to by the application, the clear that

    // happened after it was composited should be ignored by the compositor.

    if (m_context->layerComposited() && !m_attributes.preserveDrawingBuffer) {

1197 m_context->paint~~Composited~~ResultsToCanvas(canvas->buffer());

1197 m_context->paintRenderingResultsToCanvas(canvas->buffer());

        canvas->makePresentationCopy();

    } else

Source/WebCore/rendering/RenderHTMLCanvas.cpp

@@void RenderHTMLCanvas::paintReplaced(PaintInfo& paintInfo, const LayoutPoint& pa

        page().addRelevantRepaintedObject(this, intersection(replacedContentRect, contentBoxRect));

    InterpolationQualityMaintainer interpolationMaintainer(context, ImageQualityController::interpolationQualityFromStyle(style()));

95

96 canvasElement().setIsSnapshotting(paintInfo.paintBehavior.contains(PaintBehavior::Snapshotting));

9597 canvasElement().paint(context, replacedContentRect);

98 canvasElement().setIsSnapshotting(false);

}

void RenderHTMLCanvas::canvasSizeChanged()