Compute a more correct "screen scope" transform for SVGSVGElement

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

Index: third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp b/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
index 79dcc61cc0e289a71c46106bd7cefbed214a7be9..5cdb55aa470102e089166c9dd519594f4026d229 100644
--- a/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGSVGElement.cpp
@@ -450,57 +450,18 @@ SVGTransformTearOff* SVGSVGElement::createSVGTransformFromMatrix(
   return SVGTransformTearOff::create(matrix);
 }
 
-AffineTransform SVGSVGElement::localCoordinateSpaceTransform(
-    SVGElement::CTMScope mode) const {
-  AffineTransform viewBoxTransform;
-  if (!hasEmptyViewBox()) {
-    FloatSize size = currentViewportSize();
-    viewBoxTransform = viewBoxToViewTransform(size.width(), size.height());
-  }
-
+AffineTransform SVGSVGElement::localCoordinateSpaceTransform() const {
   AffineTransform transform;
   if (!isOutermostSVGSVGElement()) {
     SVGLengthContext lengthContext(this);
     transform.translate(m_x->currentValue()->value(lengthContext),
                         m_y->currentValue()->value(lengthContext));
-  } else if (mode == SVGElement::ScreenScope) {
-    if (LayoutObject* layoutObject = this->layoutObject()) {
-      FloatPoint location;
-      float zoomFactor = 1;
-
-      // At the SVG/HTML boundary (aka LayoutSVGRoot), we apply the
-      // localToBorderBoxTransform to map an element from SVG viewport
-      // coordinates to CSS box coordinates.  LayoutSVGRoot's localToAbsolute
-      // method expects CSS box coordinates.  We also need to adjust for the
-      // zoom level factored into CSS coordinates (bug #96361).
-      if (layoutObject->isSVGRoot()) {
-        location = toLayoutSVGRoot(layoutObject)
-                       ->localToBorderBoxTransform()
-                       .mapPoint(location);
-        zoomFactor = 1 / layoutObject->style()->effectiveZoom();
-      }
-
-      // Translate in our CSS parent coordinate space
-      // FIXME: This doesn't work correctly with CSS transforms.
-      location = layoutObject->localToAbsolute(location, UseTransforms);
-      location.scale(zoomFactor, zoomFactor);
-
-      // Be careful here! localToBorderBoxTransform() included the x/y offset
-      // coming from the viewBoxToViewTransform(), so we have to subtract it
-      // here (original cause of bug #27183)
-      transform.translate(location.x() - viewBoxTransform.e(),
-                          location.y() - viewBoxTransform.f());
-
-      // Respect scroll offset.
-      if (FrameView* view = document().view()) {
-        LayoutSize scrollOffset(view->getScrollOffset());
-        scrollOffset.scale(zoomFactor);
-        transform.translate(-scrollOffset.width(), -scrollOffset.height());
-      }
-    }
   }
-
-  return transform.multiply(viewBoxTransform);
+  if (!hasEmptyViewBox()) {
+    FloatSize size = currentViewportSize();
+    transform.multiply(viewBoxToViewTransform(size.width(), size.height()));
+  }
+  return transform;
 }
 
 bool SVGSVGElement::layoutObjectIsNeeded(const ComputedStyle& style) {