make sure mapbox-gl canvas does not inherit left and top css

- e.g. in rreusser's plotly-mock-viewer

Author: etpinard

src/plots/mapbox/mapbox.js

@@ -111,10 +111,14 @@ proto.createMap = function(calcData, fullLayout, resolve, reject) {
     });
 
     // clear navigation container
-    var className = constants.controlContainerClassName,
-        controlContainer = self.div.getElementsByClassName(className)[0];
+    var className = constants.controlContainerClassName;
+    var controlContainer = self.div.getElementsByClassName(className)[0];
     self.div.removeChild(controlContainer);
 
+    // make sure canvas does not inherit left and top css
+    map._canvas.canvas.style.left = '0px';
+    map._canvas.canvas.style.top = '0px';
+
     self.rejectOnError(reject);
 
     map.once('load', function() {
@@ -176,7 +180,6 @@ proto.createMap = function(calcData, fullLayout, resolve, reject) {
 
     map.on('dragstart', unhover);
     map.on('zoomstart', unhover);
-
 };
 
 proto.updateMap = function(calcData, fullLayout, resolve, reject) {