🔪 ax._min / ax._max logic for rangeslider

- questionable commit, especially the part in autorange.js,
  but this doesn't make any test fail ?!?

Author: etpinard

src/components/rangeslider/calc_autorange.js

@@ -21,13 +21,10 @@ module.exports = function calcAutorange(gd) {
     // this step in subsequent draw calls.
 
     for(var i = 0; i < axes.length; i++) {
-        var ax = axes[i],
-            opts = ax[constants.name];
+        var ax = axes[i];
+        var opts = ax[constants.name];
 
-        // Don't try calling getAutoRange if _min and _max are filled in.
-        // This happens on updates where the calc step is skipped.
-
-        if(opts && opts.visible && opts.autorange && ax._min.length && ax._max.length) {
+        if(opts && opts.visible && opts.autorange) {
             opts._input.autorange = true;
             opts._input.range = opts.range = getAutoRange(gd, ax);
         }

src/plots/cartesian/autorange.js

@@ -258,11 +258,7 @@ function doAutoRange(gd, ax) {
         var axeRangeOpts = ax._anchorAxis.rangeslider[ax._name];
         if(axeRangeOpts) {
             if(axeRangeOpts.rangemode === 'auto') {
-                if(hasDeps) {
-                    axeRangeOpts.range = getAutoRange(ax);
-                } else {
-                    axeRangeOpts.range = ax._rangeInitial ? ax._rangeInitial.slice() : ax.range.slice();
-                }
+                axeRangeOpts.range = getAutoRange(gd, ax);
             }
         }
         axIn = ax._anchorAxis._input;