Changing the android check from looking at the userAgent to checking for the...

Changing the android check from looking at the userAgent to checking for the failing JSON.parse(null).

This will capture a wider range of devices and checks for what makes things fail instead of one browser that can be faked.

browserid/static/include.js

@@ -579,32 +579,8 @@
     return message;
   }
 
-  function getAndroidVersion() {
-    var rv = -1; // Return value assumes failure.
-    var ua = navigator.userAgent;
-    if (ua.match(/Android/)) {
-      var re = new RegExp("Android ([0-9]{1,}[\.0-9]{0,})");
-      if (re.exec(ua) != null)
-        rv = parseFloat(RegExp.$1);
-    }
-
-    return rv;
-  }
-
-  function checkAndroid() {
-    var androidVersion = getAndroidVersion(),
-        androidNoSupport = androidVersion > -1 && androidVersion < 3,
-        message;
-
-    if(androidNoSupport) {
-      message = "Unfortunately, your version of the Android browser is not yet supported.";
-    }
-
-    return message;
-  }
-
   function explicitNosupport() {
-    var message = checkIE() || checkAndroid();
+    var message = checkIE();
 
     if (message) {
        message += "\nWe are working hard to bring BrowserID support to your browser!";
@@ -617,13 +593,26 @@
   function checkRequirements() {
     var localStorage = 'localStorage' in window && window['localStorage'] !== null;
     var postMessage = !!window.postMessage;
+    var json = true;
+
+    if(window.JSON) {
+      // If there is no native JSON support, we use Crockford's JSON2 library.
+      try {
+        // Android < 3 blows up on this.
+        JSON.parse(null);
+      }
+      catch(e) {
+        json = false;
+      }
+    }
+
     var explicitNo = explicitNosupport()
 
-    if(!explicitNo && !(localStorage && postMessage)) {
+    if(!explicitNo && !(localStorage && postMessage && json)) {
       alert("Unfortunately, your browser does not meet the minimum HTML5 support required for BrowserID.");
     }
 
-    return localStorage && postMessage && !(explicitNo);
+    return localStorage && postMessage && json && !(explicitNo);
   }
 
   // this is for calls that are non-interactive