mWebView.getSettings().setJavaScriptEnabled(true);

mWebView.setWebChromeClient(new WebChromeClient() {


   @Override
   public void onProgressChanged(WebView view, int newProgress) {
    if (newProgress == 100) {
     mBar.setVisibility(View.GONE);
    } else {
     mBar.setVisibility(View.VISIBLE);
     mBar.setProgress(newProgress);
    }
    super.onProgressChanged(view, newProgress);
   }

   //For Android API < 11 (3.0 OS)
   public void openFileChooser(ValueCallback<Uri> valueCallback) {
    uploadMessage = valueCallback;
    openImageChooserActivity();
   }

   //For Android API >= 11 (3.0 OS)
   public void openFileChooser(ValueCallback<Uri> valueCallback, String acceptType, String capture) {
    uploadMessage = valueCallback;
    openImageChooserActivity();
   }

   //For Android API >= 21 (5.0 OS)
   @Override
   public boolean onShowFileChooser(WebView webView, ValueCallback<Uri[]> filePathCallback, WebChromeClient.FileChooserParams fileChooserParams) {
    uploadMessageAboveL = filePathCallback;
    openImageChooserActivity();
    return true;
   }

  }); 

private void openImageChooserActivity() {
  Intent i = new Intent(Intent.ACTION_GET_CONTENT);
  i.addCategory(Intent.CATEGORY_OPENABLE);
  i.setType("image/*");
  startActivityForResult(Intent.createChooser(i, "Image Chooser"), FILE_CHOOSER_RESULT_CODE);
 } 

@Override
 protected void onActivityResult(int requestCode, int resultCode, Intent data) {
  super.onActivityResult(requestCode, resultCode, data);
  if (requestCode == FILE_CHOOSER_RESULT_CODE) {
   if (null == uploadMessage && null == uploadMessageAboveL) return;
   Uri result = data == null || resultCode != RESULT_OK ? null : data.getData();
   if (uploadMessageAboveL != null) {
    onActivityResultAboveL(requestCode, resultCode, data);
   } else if (uploadMessage != null) {
    uploadMessage.onReceiveValue(result);
    uploadMessage = null;
   }
  }
 }

 @TargetApi(Build.VERSION_CODES.LOLLIPOP)
 private void onActivityResultAboveL(int requestCode, int resultCode, Intent intent) {
  if (requestCode != FILE_CHOOSER_RESULT_CODE || uploadMessageAboveL == null)
   return;
  Uri[] results = null;
  if (resultCode == Activity.RESULT_OK) {
   if (intent != null) {
    String dataString = intent.getDataString();
    ClipData clipData = intent.getClipData();
    if (clipData != null) {
     results = new Uri[clipData.getItemCount()];
     for (int i = 0; i < clipData.getItemCount(); i++) {
      ClipData.Item item = clipData.getItemAt(i);
      results[i] = item.getUri();
     }
    }
    if (dataString != null)
     results = new Uri[]{Uri.parse(dataString)};
   }
  }
  uploadMessageAboveL.onReceiveValue(results);
  uploadMessageAboveL = null;
 }