Update everything that can't be polyfilled in old IE.

Replace PointerMap.size getter with a size method.
Quote properties named delete.

src/capture.js

@@ -32,7 +32,7 @@
       dispatcher.releaseCapture(pointerId, this);
     };
   }
-  if (!Element.prototype.setPointerCapture) {
+  if (window.Element && !Element.prototype.setPointerCapture) {
     Object.defineProperties(Element.prototype, {
       'setPointerCapture': {
         value: s

src/mouse.js

@@ -94,7 +94,7 @@
       this.cleanupMouse();
     },
     cleanupMouse: function() {
-      pointermap.delete(this.POINTER_ID);
+      pointermap['delete'](this.POINTER_ID);
     }
   };
 

src/ms.js

@@ -41,7 +41,7 @@
       return e;
     },
     cleanup: function(id) {
-      pointermap.delete(id);
+      pointermap['delete'](id);
     },
     MSPointerDown: function(inEvent) {
       pointermap.set(inEvent.pointerId, inEvent);

src/touch.js

@@ -54,11 +54,11 @@
       }
     },
     elementRemoved: function(el) {
-      this.scrollType.delete(el);
+      this.scrollType['delete'](el);
       dispatcher.unlisten(el, this.events);
       // remove touch-action from shadow
       allShadows(el).forEach(function(s) {
-        this.scrollType.delete(s);
+        this.scrollType['delete'](s);
         dispatcher.unlisten(s, this.events);
       }, this);
     },
@@ -291,7 +291,7 @@
       this.cleanUpPointer(inPointer);
     },
     cleanUpPointer: function(inPointer) {
-      pointermap.delete(inPointer.pointerId);
+      pointermap['delete'](inPointer.pointerId);
       this.removePrimaryPointer(inPointer);
     },
     // prevent synth mouse events from creating pointer events