title: input file to Base64 failed on android devices
body: <p>I am creating an application, where the user can select a picture from the local directory then I convert it to base64.
  I wrote a javascript code that do this operation, and everything gonna fine on desktop browsers but it fail on android devices.</p>
  
  <p>JS code:</p>
  
  <pre><code>function convert_input_image_base64(input, callback) {
  
          if (input.files &amp;&amp; input.files[0]) {
              var mime_type = input.files[0]["type"];
              if (mime_type === "image/png" || mime_type === "image/jpg" || mime_type === "image/jpeg") {
                  var reader = new FileReader();
                  reader.onload = function(e) {
                      alert(e.target.result);
                      callback(e.target.result);
                  };
              }
              else {
                  callback("INVALID_EXTENSION");
              }
              reader.readAsDataURL(input.files[0]);
          }
          else
              callback("ERROR");
      }
   $("#mobile_image_input").on("change", function() {
     convert_input_image_base64(this,function(response){
      alert(response);
     });
  });
  </code></pre>