Bug 107656 – Coordinated Graphics: CoordinatedLayerTreeHost::sizeDidChange uses the size in css unit, not device unit.

• Status: RESOLVED
• Resolution: INVALID
• Component: Layout and Rendering

[Dongseong Hwang]

CoordinatedLayerTreeHost::sizeDidChange set the size of WebPage to GraphicsLayer, and the size is in device units.

void CoordinatedLayerTreeHost::sizeDidChange(const WebCore::IntSize& newSize)
{
    if (m_rootLayer->size() == newSize)
        return;

    m_rootLayer->setSize(newSize);

    // If the newSize exposes new areas of the non-composited content a setNeedsDisplay is needed
    // for those newly exposed areas.
    FloatSize oldSize = m_nonCompositedContentLayer->size();
    m_nonCompositedContentLayer->setSize(newSize);
    ...
}

But all other child layer has the size in css unit.

I don't find any artifact yet, because TBS paints entire contents for non composited layer. But it is a potential bug.

In addition, I'm not sure if WebPage should use the size in device unit.

[Dongseong Hwang]

I think it may be related to Bug 104906

[Dongseong Hwang]

Bug 111407 works in progress about refactoring CoordinatedLayerTreeHost::sizeDidChange.