Avoid requiring a recalc to update compositing state for iframes

Source/core/rendering/RenderLayerCompositor.cpp

Index: Source/core/rendering/RenderLayerCompositor.cpp
diff --git a/Source/core/rendering/RenderLayerCompositor.cpp b/Source/core/rendering/RenderLayerCompositor.cpp
index 9c3450767be33ec499b3828a0f62cd3748086cd9..7593af6c2d1b2e5695e3a841a67d88493783665a 100644
--- a/Source/core/rendering/RenderLayerCompositor.cpp
+++ b/Source/core/rendering/RenderLayerCompositor.cpp
@@ -2485,8 +2485,10 @@ void RenderLayerCompositor::notifyIFramesOfCompositingChange()
 
     // Compositing also affects the answer to RenderIFrame::requiresAcceleratedCompositing(), so
     // we need to schedule a style recalc in our parent document.
-    if (HTMLFrameOwnerElement* ownerElement = m_renderView->document().ownerElement())
+    if (HTMLFrameOwnerElement* ownerElement = m_renderView->document().ownerElement()) {
+        ownerElement->document().renderView()->compositor()->setNeedsToRecomputeCompositingRequirements();
         ownerElement->scheduleLayerUpdate();

[shawnsingh, 2014/02/06 13:32:16]

I'm curious what else does scheduleLayerUpdate do other than flag a
setNeedsRecalcStyle?

If it doesn't do anything meaningfully significant w.r.t. iframe compositing
changes (and if it does, it shouldn't), then I think we could just remove this
entire function, and replace it with a much simpler
setNeedsToRecoputeCompositingRequirements like you added here.

[dstockwell, 2014/02/07 03:22:03]

That's all it does. I think we can remove it, but I think we should do it in a
follow up so that this more surgical change can be merged to M33.

+    }
 }
 
 bool RenderLayerCompositor::layerHas3DContent(const RenderLayer* layer) const