Fallback to jsonp proxy if browser doesn't support cors xhr/image

src/proxyimagecontainer.js

@@ -1,38 +1,18 @@
 function ProxyImageContainer(src, proxy) {
-    var callbackName = "html2canvas_" + proxyImageCount++;
     var script = document.createElement("script");
     var link = document.createElement("a");
     link.href = src;
     src = link.href;
-    var requestUrl = proxy + ((proxy.indexOf("?") > -1) ? "&" : "?" ) + 'url=' + encodeURIComponent(src) + '&callback=' + callbackName;
     this.src = src;
     this.image = new Image();
     var self = this;
     this.promise = new Promise(function(resolve, reject) {
+        self.image.crossOrigin = "Anonymous";
         self.image.onload = resolve;
         self.image.onerror = reject;
 
-        window[callbackName] = function(a){
-            if (a.substring(0,6) === "error:"){
-                reject();
-            } else {
-                self.image.src = a;
-            }
-            window[callbackName] = undefined; // to work with IE<9  // NOTE: that the undefined callback property-name still exists on the window object (for IE<9)
-            try {
-                delete window[callbackName];  // for all browser that support this
-            } catch(ex) {}
-            script.parentNode.removeChild(script);
-        };
-        script.setAttribute("type", "text/javascript");
-        script.setAttribute("src", requestUrl);
-        document.body.appendChild(script);
-    })['catch'](function() {
-        var dummy = new DummyImageContainer(src);
-        return dummy.promise.then(function(image) {
-            self.image = image;
-        });
+        new ProxyURL(src, proxy, document).then(function(url) {
+            self.image.src = url;
+        })['catch'](reject);
     });
 }
-
-var proxyImageCount = 0;