rm useless logic in gl3d .plot

- setting paperdiv style is done in the
  layoutStyles plot_api subroutine

Author: etpinard

src/plots/gl3d/index.js

@@ -37,21 +37,13 @@ exports.plot = function plotGl3d(gd) {
         fullData = gd._fullData,
         sceneIds = Plots.getSubplotIds(fullLayout, 'gl3d');
 
-    fullLayout._paperdiv.style({
-        width: fullLayout.width + 'px',
-        height: fullLayout.height + 'px'
-    });
-
-    gd._context.setBackground(gd, fullLayout.paper_bgcolor);
-
     for(var i = 0; i < sceneIds.length; i++) {
         var sceneId = sceneIds[i],
             fullSceneData = Plots.getSubplotData(fullData, 'gl3d', sceneId),
             sceneLayout = fullLayout[sceneId],
             scene = sceneLayout._scene;
 
-        // If Scene is not instantiated, create one!
-        if(scene === undefined) {
+        if(!scene) {
             initAxes(gd, sceneLayout);
 
             scene = new Scene({