Bug 1573268 - remove the varcache definition for svg.transform-box.enabled. r=njn

svg.transform-box.enabled is already a static pref, so I removed the varcache definition of it in nsLayoutUtils.

Differential Revision: https://phabricator.services.mozilla.com/D41850

--HG--
extra : moz-landing-system : lando

layout/base/nsLayoutUtils.cpp

@@ -183,8 +183,6 @@ bool nsLayoutUtils::gPreventAssertInCompareTreePosition = false;
 typedef ScrollableLayerGuid::ViewID ViewID;
 typedef nsStyleTransformMatrix::TransformReferenceBox TransformReferenceBox;
 
-/* static */
-bool nsLayoutUtils::sSVGTransformBoxEnabled;
 /* static */
 uint32_t nsLayoutUtils::sIdlePeriodDeadlineLimit;
 /* static */
@@ -7963,8 +7961,6 @@ size_t nsLayoutUtils::SizeOfTextRunsForFrames(nsIFrame* aFrame,
 
 /* static */
 void nsLayoutUtils::Initialize() {
-  Preferences::AddBoolVarCache(&sSVGTransformBoxEnabled,
-                               "svg.transform-box.enabled");
   Preferences::AddUintVarCache(&sIdlePeriodDeadlineLimit,
                                "layout.idle_period.time_limit",
                                DEFAULT_IDLE_PERIOD_TIME_LIMIT);

layout/base/nsLayoutUtils.h

@@ -2442,8 +2442,6 @@ class nsLayoutUtils {
 
   static bool FontSizeInflationEnabled(nsPresContext* aPresContext);
 
-  static bool SVGTransformBoxEnabled() { return sSVGTransformBoxEnabled; }
-
   static uint32_t IdlePeriodDeadlineLimit() { return sIdlePeriodDeadlineLimit; }
 
   static uint32_t QuiescentFramesBeforeIdlePeriod() {
@@ -2994,7 +2992,6 @@ class nsLayoutUtils {
       const nsIFrame* aFrame);
 
  private:
-  static bool sSVGTransformBoxEnabled;
   static uint32_t sIdlePeriodDeadlineLimit;
   static uint32_t sQuiescentFramesBeforeIdlePeriod;
 

layout/style/nsStyleTransformMatrix.cpp

@@ -13,6 +13,7 @@
 #include "nsPresContext.h"
 #include "nsSVGUtils.h"
 #include "mozilla/ServoBindings.h"
+#include "mozilla/StaticPrefs_svg.h"
 #include "mozilla/StyleAnimationValue.h"
 #include "gfxMatrix.h"
 #include "gfxQuaternion.h"
@@ -47,7 +48,7 @@ void TransformReferenceBox::EnsureDimensionsAreCached() {
   mIsCached = true;
 
   if (mFrame->GetStateBits() & NS_FRAME_SVG_LAYOUT) {
-    if (!nsLayoutUtils::SVGTransformBoxEnabled()) {
+    if (!StaticPrefs::svg_transform_box_enabled()) {
       mX = -mFrame->GetPosition().x;
       mY = -mFrame->GetPosition().y;
       Size contextSize = nsSVGUtils::GetContextSize(mFrame);