Delay in loading Html Page(WebView) from assets folder in real android device

Question

WebView takes approx. 10 second time to load Html Page from Assets folder in real android device greater than 4.3.... My WebView activity are as follows:-

import android.app.AlertDialog;
import android.content.DialogInterface;

import android.content.Intent;
import android.graphics.Bitmap;

import android.os.Build;

import android.os.Bundle;

import android.support.v7.app.ActionBarActivity;

import android.support.v7.widget.Toolbar;

import android.view.MenuItem;

import android.view.View;
import android.webkit.WebSettings;

import android.webkit.WebView;

import android.webkit.WebViewClient;
import android.widget.TextView;

import android.widget.Toast;

 public class Activity_WebView extends ActionBarActivity {

boolean loadingFinished = true;
boolean redirect = false;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_load_webview);

    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);
    getSupportActionBar().setDisplayShowTitleEnabled(true);
    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setHomeButtonEnabled(true);

    TextView app_Title = (TextView) toolbar.findViewById(R.id.toolbar_title);
    app_Title.setVisibility(View.VISIBLE);

    Intent intent = getIntent();
    String TITLE = intent.getStringExtra("Title");
    String URL_PATH = intent.getStringExtra("Url_Path");

    WebView webview = (WebView) findViewById(R.id.webView);

    webview.getSettings().setJavaScriptEnabled(true);
    webview.setBackgroundColor(getResources().getColor(android.R.color.transparent));
    webview.getSettings().setCacheMode(WebSettings.LOAD_NO_CACHE);
    webview.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH);

    try {
        if (Build.VERSION.SDK_INT > 14) {
            webview.setLayerType(WebView.LAYER_TYPE_SOFTWARE, null);
        }
    } catch (Exception e) { e.printStackTrace();}



    GlobalVariablesCollection.globalPD = CustomProgressBarDialog.showProgressDialog(Activity_WebView.this);
    final AlertDialog alertDialog = new AlertDialog.Builder(this).create();

    app_Title.setText(TITLE);
    webview.loadUrl(URL_PATH);
    webview.setWebViewClient(new WebViewClient() {

        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            if (!loadingFinished) {
                redirect = true;
            }

            loadingFinished = false;
            view.loadUrl(url);
            return true;
        }

        @Override
        public void onPageStarted(WebView view, String url, Bitmap facIcon) {
            loadingFinished = false;
            //SHOW LOADING IF IT IS NOT ALREADY VISIBLE
            GlobalVariablesCollection.globalPD.show();
        }

        @Override
        public void onPageFinished(WebView view, String url) {
            if (!redirect) {
                loadingFinished = true;
            }

            if (loadingFinished && !redirect) {
                //HIDE LOADING IT HAS FINISHED
                GlobalVariablesCollection.globalPD.dismiss();

            } else {
                redirect = false;
            }

        }

        @Override
        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Toast.makeText(getApplicationContext(), "Oh no! " + description, Toast.LENGTH_SHORT).show();
            alertDialog.setTitle("Error");
            alertDialog.setMessage(description);
            alertDialog.setButton("OK", new DialogInterface.OnClickListener() {
                public void onClick(DialogInterface dialog, int which) {
                    return;
                }
            });
            alertDialog.show();
        }
    });

}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    switch (item.getItemId()) {
        case android.R.id.home:
            this.finish();
            return true;
        default:
            return super.onOptionsItemSelected(item);
    }
}

}

My Requirement: WebView should display Html Page on

onPageFinished