[CSS Typed OM] Refactor is2D handling in CSSTransformComponents to match new spec

third_party/WebKit/Source/core/css/cssom/CSSPerspective.h

Index: third_party/WebKit/Source/core/css/cssom/CSSPerspective.h
diff --git a/third_party/WebKit/Source/core/css/cssom/CSSPerspective.h b/third_party/WebKit/Source/core/css/cssom/CSSPerspective.h
index 990911511f7e1df0c562a9361f27332a8b00cbe8..f27abc30105e6be19f6c7f425a8e60f54e183e53 100644
--- a/third_party/WebKit/Source/core/css/cssom/CSSPerspective.h
+++ b/third_party/WebKit/Source/core/css/cssom/CSSPerspective.h
@@ -32,6 +32,11 @@ class CORE_EXPORT CSSPerspective final : public CSSTransformComponent {
   CSSNumericValue* length() { return length_.Get(); }
   void setLength(CSSNumericValue*, ExceptionState&);
 
+  // From CSSTransformComponent
+  // Setting is2D for CSSPerspective does nothing.
+  // https://drafts.css-houdini.org/css-typed-om/#dom-cssskew-is2d
+  void setIs2D(bool is2D) final {}
+
   // Internal methods - from CSSTransformComponent.
   TransformComponentType GetType() const final { return kPerspectiveType; }
   // TODO: Implement AsMatrix for CSSPerspective.
@@ -44,7 +49,8 @@ class CORE_EXPORT CSSPerspective final : public CSSTransformComponent {
   }
 
  private:
-  CSSPerspective(CSSNumericValue* length) : length_(length) {}
+  CSSPerspective(CSSNumericValue* length)
+      : CSSTransformComponent(false /* is2D */), length_(length) {}
 
   Member<CSSNumericValue> length_;
 };