Add connectivity check using system stack.

chrome/android/java/src/org/chromium/chrome/browser/feedback/ConnectivityChecker.java

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 package org.chromium.chrome.browser.feedback;
 
+import android.os.AsyncTask;
+
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
+import org.chromium.base.Log;
 import org.chromium.base.ThreadUtils;
 import org.chromium.base.VisibleForTesting;
 import org.chromium.chrome.browser.profiles.Profile;
 
+import java.io.IOException;
+import java.net.HttpURLConnection;
+import java.net.MalformedURLException;
+import java.net.URL;
+
 /**
  * A utility class for checking if the device is currently connected to the Internet.
  */
 @JNINamespace("chrome::android")
 public final class ConnectivityChecker {
-    private static final String DEFAULT_NO_CONTENT_URL = "http://clients4.google.com/generate_204";
+    private static final String TAG = "ConnectivityChecker";
+
+    private static final String DEFAULT_HTTP_NO_CONTENT_URL =
+            "http://clients4.google.com/generate_204";
+    private static final String DEFAULT_HTTPS_NO_CONTENT_URL =
+            "https://clients4.google.com/generate_204";
 
     /**
      * A callback for whether the device is currently connected to the Internet.
      */
     public interface ConnectivityCheckerCallback {
         /**
          * Called when the result of the connectivity check is ready.
          */
         void onResult(boolean connected);
     }
 
     /**
      * Starts an asynchronous request for checking whether the device is currently connected to the
-     * Internet. The result passed to the callback denotes whether the attempt to connect to the
-     * server was successful.
+     * Internet using the Android system network stack. The result passed to the callback denotes
+     * whether the attempt to connect to the server was successful.
      *
      * If the profile or URL is invalid, the callback will be called with false.
      * The server reply for the URL must respond with HTTP 204 without any redirects for the
+     * connectivity check to be successful.
+     *
+     * This method takes ownership of the callback object until the callback has happened.
+     * This method must be called on the main thread.

[Yaron, 2015/05/15 15:57:50]

If it must be called on UI thread why are you posting to UI thread?

[nyquist, 2015/05/15 16:32:18]

Because I believe that as a caller of this API, it is awkward to get the
callback before your method call has completed.

[Yaron, 2015/05/15 17:06:04]

Fair enough

+     * @param timeoutMs number of milliseconds to wait before giving up waiting for a connection.
+     * @param callback the callback which will get the result.
+     */
+    public static void checkConnectivitySystemNetworkStack(
+            boolean useHttps, int timeoutMs, final ConnectivityCheckerCallback callback) {
+        try {
+            URL url = useHttps ? new URL(DEFAULT_HTTPS_NO_CONTENT_URL)
+                               : new URL(DEFAULT_HTTP_NO_CONTENT_URL);
+            checkConnectivitySystemNetworkStack(url, timeoutMs, callback);
+        } catch (MalformedURLException e) {
+            Log.w(TAG, "Failed to predefined URL: " + e);
+            ThreadUtils.postOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    callback.onResult(false);
+                }
+            });
+        }
+    }
+
+    static void checkConnectivitySystemNetworkStack(
+            final URL url, final int timeoutMs, final ConnectivityCheckerCallback callback) {
+        new AsyncTask<String, Void, Boolean>() {
+            @Override
+            protected Boolean doInBackground(String... strings) {
+                try {
+                    HttpURLConnection conn = (HttpURLConnection) url.openConnection();
+                    conn.setInstanceFollowRedirects(false);
+                    conn.setRequestMethod("GET");
+                    conn.setDoInput(false);
+                    conn.setDoOutput(false);
+                    conn.setConnectTimeout(timeoutMs);
+                    conn.setReadTimeout(timeoutMs);
+
+                    conn.connect();
+                    int responseCode = conn.getResponseCode();
+                    return responseCode == HttpURLConnection.HTTP_NO_CONTENT;
+                } catch (IOException e) {
+                    return false;
+                }
+            }
+
+            @Override
+            protected void onPostExecute(Boolean connected) {
+                callback.onResult(connected);
+            }
+        }.execute();

[Yaron, 2015/05/15 15:57:50]

can you use THREAD_POOL_EXECUTOR to not block the serial one?

[nyquist, 2015/05/15 16:32:18]

Sorry. Yes! Done.

+    }
+
+    /**
+     * Starts an asynchronous request for checking whether the device is currently connected to the
+     * Internet using the Chrome network stack. The result passed to the callback denotes whether
+     *the
+     * attempt to connect to the server was successful.
+     *
+     * If the profile or URL is invalid, the callback will be called with false.
+     * The server reply for the URL must respond with HTTP 204 without any redirects for the
      * connectivity check to be successful.
      *
      * This method takes ownership of the callback object until the callback has happened.
      * This method must be called on the main thread.
      * @param profile the context to do the check in.
      * @param timeoutMs number of milliseconds to wait before giving up waiting for a connection.
      * @param callback the callback which will get the result.
      */
-    public static void checkConnectivity(
-            Profile profile, long timeoutMs, ConnectivityCheckerCallback callback) {
-        checkConnectivity(profile, DEFAULT_NO_CONTENT_URL, timeoutMs, callback);
+    public static void checkConnectivityChromeNetworkStack(Profile profile, boolean useHttps,
+            long timeoutMs, ConnectivityCheckerCallback callback) {
+        String url = useHttps ? DEFAULT_HTTPS_NO_CONTENT_URL : DEFAULT_HTTP_NO_CONTENT_URL;
+        checkConnectivityChromeNetworkStack(profile, url, timeoutMs, callback);
     }
 
     @VisibleForTesting
-    static void checkConnectivity(
+    static void checkConnectivityChromeNetworkStack(
             Profile profile, String url, long timeoutMs, ConnectivityCheckerCallback callback) {
         ThreadUtils.assertOnUiThread();
         nativeCheckConnectivity(profile, url, timeoutMs, callback);
     }
 
     @CalledByNative
     private static void executeCallback(Object callback, boolean connected) {
         ((ConnectivityCheckerCallback) callback).onResult(connected);
     }
 
     private ConnectivityChecker() {}
 
     private static native void nativeCheckConnectivity(
             Profile profile, String url, long timeoutMs, ConnectivityCheckerCallback callback);
 }