From 7f57b96c839be89cd15ff9c646b506cec0c22356 Mon Sep 17 00:00:00 2001
From: Botond Ballo <botond@mozilla.com>
Date: Fri, 9 Mar 2018 17:26:24 -0500
Subject: [PATCH] Bug 1443092 - Avoid calling SVGAnimatedEnumeration::AnimVal()
 from nsSVGUtils::GetBBox(). r=jwatt, a=RyanVM

AnimVal() is a DOM getter, and it flushes animations, which we don't want
in GetBBox() which is called from display list building cide and
FrameLayerBuilder.

MozReview-Commit-ID: DWgm7wAV7C0
---
 dom/svg/SVGClipPathElement.cpp | 7 +++++++
 dom/svg/SVGClipPathElement.h   | 4 ++++
 layout/svg/nsSVGUtils.cpp      | 3 +--
 3 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/dom/svg/SVGClipPathElement.cpp b/dom/svg/SVGClipPathElement.cpp
index 60d72fdf04..682d1271e1 100644
--- a/dom/svg/SVGClipPathElement.cpp
+++ b/dom/svg/SVGClipPathElement.cpp
@@ -50,6 +50,13 @@ SVGClipPathElement::GetEnumInfo()
                             ArrayLength(sEnumInfo));
 }
 
+bool
+SVGClipPathElement::IsUnitsObjectBoundingBox() const
+{
+  return mEnumAttributes[CLIPPATHUNITS].GetAnimValue() == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX;
+}
+
+
 //----------------------------------------------------------------------
 // nsIDOMNode methods
 
diff --git a/dom/svg/SVGClipPathElement.h b/dom/svg/SVGClipPathElement.h
index d84f5b30fb..2d9f4c15e5 100644
--- a/dom/svg/SVGClipPathElement.h
+++ b/dom/svg/SVGClipPathElement.h
@@ -36,6 +36,10 @@ public:
   // WebIDL
   already_AddRefed<SVGAnimatedEnumeration> ClipPathUnits();
 
+  // This is an internal method that does not flush style, and thus
+  // the answer may be out of date if there's a pending style flush.
+  bool IsUnitsObjectBoundingBox() const;
+
 protected:
 
   enum { CLIPPATHUNITS };
diff --git a/layout/svg/nsSVGUtils.cpp b/layout/svg/nsSVGUtils.cpp
index ff74d5bafc..344ebf645a 100644
--- a/layout/svg/nsSVGUtils.cpp
+++ b/layout/svg/nsSVGUtils.cpp
@@ -1127,8 +1127,7 @@ nsSVGUtils::GetBBox(nsIFrame *aFrame, uint32_t aFlags)
       if (clipPathFrame && isOK) {
         SVGClipPathElement *clipContent = 
           static_cast<SVGClipPathElement*>(clipPathFrame->GetContent());
-        RefPtr<SVGAnimatedEnumeration> units = clipContent->ClipPathUnits();
-        if (units->AnimVal() == SVG_UNIT_TYPE_OBJECTBOUNDINGBOX) {
+        if (clipContent->IsUnitsObjectBoundingBox()) {
           matrix.Translate(gfxPoint(x, y));
           matrix.Scale(width, height);
         } else if (aFrame->GetType() == nsGkAtoms::svgForeignObjectFrame) {