Use same layout logic in animations for deciding whether an element can transform

third_party/WebKit/Source/core/layout/LayoutObject.h

Index: third_party/WebKit/Source/core/layout/LayoutObject.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutObject.h b/third_party/WebKit/Source/core/layout/LayoutObject.h
index 24d0de5a637d374eb96825d9339f2475ed226889..c7bbc183dcf59ef24b1769791126c5311ded7513 100644
--- a/third_party/WebKit/Source/core/layout/LayoutObject.h
+++ b/third_party/WebKit/Source/core/layout/LayoutObject.h
@@ -712,6 +712,7 @@ public:
     bool hasClipRelatedProperty() const { return hasClip() || hasOverflowClip() || style()->containsPaint(); }
 
     bool hasTransformRelatedProperty() const { return m_bitfields.hasTransformRelatedProperty(); }
+    bool canTransform() const { return isBox(); }

[trchen, 2016/08/09 01:22:02]

SVG? For example: http://codepen.io/chriscoyier/pen/dvjhn/
I think the condition in CompositorAnimations.cpp was written in the way to not
to exclude SVG.

According to the spec:
https://drafts.csswg.org/css-transforms/#transformable-element
For CSS box model elements it is essentially isBox(). I think the standard just
spec'd after WebKit.
I'm not familiar with SVGs though. I guess all LayoutSVGModelObject supports
transform?

     bool hasMask() const { return style() && style()->hasMask(); }
     bool hasClipPath() const { return style() && style()->clipPath(); }
     bool hasHiddenBackface() const { return style() && style()->backfaceVisibility() == BackfaceVisibilityHidden; }