Switch from getBoundingClientRect to offsetLeft and offsetTop.

Author: rpaskowitz

src/plots/cartesian/graph_interact.js

@@ -855,11 +855,10 @@ function createSpikelines(hoverData, opts) {
         yLength = c0.ya._length,
         xEdge = c0.ya._boundingBox.left + (ySide === 'left' ? c0.ya._boundingBox.width : 0),
         yEdge = c0.xa._boundingBox.top + (xSide === 'top' ? c0.xa._boundingBox.height : 0),
-        outerBBox = outerContainer.node().getBoundingClientRect(),
         xFreeBase = xOffset + (ySide === 'right' ? xLength : 0),
         yFreeBase = yOffset + (xSide === 'top' ? yLength : 0),
-        xAnchoredBase = xEdge - outerBBox.left,
-        yAnchoredBase = yEdge - outerBBox.top,
+        xAnchoredBase = xEdge - outerContainer.node().offsetLeft,
+        yAnchoredBase = yEdge - outerContainer.node().offsetTop,
         xBase = c0.ya.anchor === 'free' ? xFreeBase : xAnchoredBase,
         yBase = c0.xa.anchor === 'free' ? yFreeBase : yAnchoredBase,
         contrastColor = Color.combine(opts.fullLayout.plot_bgcolor, opts.fullLayout.paper_bgcolor),