Add a use-counter for transforms using the reference box on SVG element

third_party/WebKit/Source/core/svg/SVGElement.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Nikolas Zimmermann
  * <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Alp Toker <alp@atoker.com>
  * Copyright (C) 2009 Cameron McCormack <cam@mcc.id.au>
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 278 matching lines @@
   // To be overriden by SVGGraphicsElement (or as special case SVGTextElement
   // and SVGPatternElement)
   return AffineTransform();
 }
 
 bool SVGElement::hasTransform(ApplyMotionTransform applyMotionTransform) const {
   return (layoutObject() && layoutObject()->styleRef().hasTransform()) ||
          (applyMotionTransform == IncludeMotionTransform && hasSVGRareData());
 }
 
+static inline bool transformUsesBoxSize(
+    const ComputedStyle& style,
+    ComputedStyle::ApplyTransformOrigin applyTransformOrigin) {
+  if (applyTransformOrigin == ComputedStyle::IncludeTransformOrigin &&
+      (style.transformOriginX().type() == Percent ||
+       style.transformOriginY().type() == Percent) &&
+      style.requireTransformOrigin(ComputedStyle::IncludeTransformOrigin,
+                                   ComputedStyle::ExcludeMotionPath))
+    return true;
+  if (style.transform().dependsOnBoxSize())
+    return true;
+  if (style.translate() && style.translate()->dependsOnBoxSize())
+    return true;
+  if (style.hasOffset())
+    return true;
+  return false;
+}
+
 AffineTransform SVGElement::calculateTransform(
     ApplyMotionTransform applyMotionTransform) const {
   const ComputedStyle* style =
       layoutObject() ? layoutObject()->style() : nullptr;
 
   // If CSS property was set, use that, otherwise fallback to attribute (if
   // set).
   AffineTransform matrix;
   if (style && style->hasTransform()) {
     TransformationMatrix transform;
     float zoom = style->effectiveZoom();
 
     FloatRect boundingBox = layoutObject()->objectBoundingBox();
     ComputedStyle::ApplyTransformOrigin applyTransformOrigin =
         ComputedStyle::IncludeTransformOrigin;
     // SVGTextElements need special handling for the text positioning code.
     if (isSVGTextElement(this)) {
       // Do not take into account transform-origin, or percentage values.
       boundingBox = FloatRect();
       applyTransformOrigin = ComputedStyle::ExcludeTransformOrigin;
     }
 
+    if (transformUsesBoxSize(*style, applyTransformOrigin))
+      UseCounter::count(document(), UseCounter::TransformUsesBoxSizeOnSVG);
+
     // CSS transforms operate with pre-scaled lengths. To make this work with
     // SVG (which applies the zoom factor globally, at the root level) we
     //
     //   * pre-scale the bounding box (to bring it into the same space as the
     //     other CSS values)
     //   * invert the zoom factor (to effectively compute the CSS transform
     //     under a 1.0 zoom)
     //
     // Note: objectBoundingBox is an emptyRect for elements like pattern or
     // clipPath. See the "Object bounding box units" section of
@@ skipping 945 matching lines @@
   visitor->trace(m_className);
   Element::trace(visitor);
 }
 
 const AtomicString& SVGElement::eventParameterName() {
   DEFINE_STATIC_LOCAL(const AtomicString, evtString, ("evt"));
   return evtString;
 }
 
 }  // namespace blink