Add some timing log statements

examples/interactive-filtering2.html

@@ -945,8 +945,16 @@
             const filterChange =  () => {
                 const selection = getSelection()
                 const filterFunction = buildFilter(selection, facets)
+
+                const t1 = Date.now()
                 trackToFilter.filter = filterFunction
+                const t2 = Date.now()
+                console.log(`Apply filter: ${t2 - t1}`)
+
+                const t3 = Date.now()
                 updateFilterCounts(trackToFilter, facets)
+                const t4 = Date.now()
+                console.log(`Update filter counts: ${t4 - t3}`)
             }
 
             // Apply initial filter, which might filter a few features
@@ -1153,7 +1161,14 @@
         /** Get counts for each filter, in each facet */
         function updateFilterCounts(trackToFilter, facets) {
 
-            const featuresInView = trackToFilter.getInViewFeatures()
+            const t0 = Date.now();
+
+            const featuresInView =  trackToFilter.getInViewFeatures()
+
+            const t1 = Date.now()
+            console.log(`   getInViewFeatures: ${t1 - t0}`)
+
+            const t2 = Date.now()
 
             // Reset counts
             for (let facet of facets) {
@@ -1168,6 +1183,10 @@
                 }
             }
 
+            const t3 = Date.now()
+            console.log(`   reset counts: ${t3 - t2}`)
+
+            const t4 = Date.now();
             // Loop through features counting by filter
             for (let igvFeature of featuresInView) {
 
@@ -1196,8 +1215,10 @@
                     }
                 }
             }
+            const t5 = Date.now();
+            console.log(`   count by filter: ${t5 - t4}`)
 
-
+            const t6 = Date.now()
             // Update dom
             for (let facet of facets) {
 
@@ -1218,6 +1239,9 @@
                 }
             }
 
+            const t7 = Date.now()
+            console.log(`   updateDom: ${t7 - t6}`)
+
         }