scattergl: infinite loop when there's only 1 datapoint in trace

[jessetabak]

If I create a scattergl plot with only 1 xy datapoint it will get stuck in an infinite loop.
It occurs in the allFastTypesLikely(a) function, the inc variable is always 0. In a normal scatter plot it works fine.

Since it will hang your browser I'll include the code here instead of a codepen:

index.html:

<div id="graph" style="width: 600px; height:800px"></div>
<script src="https://cdn.plot.ly/plotly-latest.js"></script>

main.js:

var div = document.getElementById('graph');

var layout = {
    title: 'My Graph'
};

var traces = [
{
    x: [1],
    y: [4],
    type: 'scattergl',
    mode: 'markers',                         
    marker: {size:8}
}];


Plotly.newPlot(
    div,  
    traces,                                     
    layout);

[etpinard]

duplicate of #1164