[Cronet] Test the libcronet that's shipped, not libcronet_test

components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java

Index: components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java
diff --git a/components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java b/components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java
index 5f844cece4722791fced01a3be049bda431f082a..8835b259e6981b2418651be5dfc65ea3b79e6650 100644
--- a/components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java
+++ b/components/cronet/android/test/javatests/src/org/chromium/net/NetworkChangeNotifierTest.java
@@ -4,28 +4,95 @@
 
 package org.chromium.net;
 
+import static android.system.OsConstants.AF_INET;
+import static android.system.OsConstants.SOCK_STREAM;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+import android.system.Os;
 import android.test.suitebuilder.annotation.SmallTest;
 
+import org.chromium.base.ThreadUtils;
 import org.chromium.base.test.util.Feature;
-import org.chromium.net.test.util.NetworkChangeNotifierTestUtil;
+
+import java.io.FileDescriptor;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.util.concurrent.atomic.AtomicBoolean;
 
 /**
- * Tests that NetworkChangeNotifier is initialized.
+ * Test NetworkChangeNotifier.
  */
 public class NetworkChangeNotifierTest extends CronetTestBase {
     /**
-     * Adds a IPAddressObserver and checks whether it receives notifications.
-     * This serves as an indirect way to test that Cronet has an active
-     * network notifier.
+     * Verify NetworkChangeNotifier signals trigger appropriate action, like
+     * aborting pending connect() jobs.
      */
     @SmallTest
     @Feature({"Cronet"})
-    public void testNetworkChangeNotifierIsInitialized() throws Exception {
+    @OnlyRunNativeCronet
+    @TargetApi(Build.VERSION_CODES.LOLLIPOP)
+    public void testNetworkChangeNotifier() throws Exception {
         CronetTestFramework testFramework = startCronetTestFramework();
         assertNotNull(testFramework);
-        // Let Cronet UI thread initialization complete so
-        // NetworkChangeNotifier is initialized for the test.
-        NetworkChangeNotifierTestUtil.flushUiThreadTaskQueue();
-        assertTrue(NetworkChangeNotifierUtil.isTestIPAddressObserverCalled());
+
+        // Os and OsConstants aren't exposed until Lollipop so we cannot run this test.
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.LOLLIPOP) {
+            return;
+        }
+
+        // Bind a listening socket to a local port. The socket won't be used to accept any
+        // connections, but rather to get connection stuck waiting to connect.
+        FileDescriptor s = Os.socket(AF_INET, SOCK_STREAM, 0);
+        // Bind to all addresses (indicated by special 0.0.0.0 value) and a random port (indicated
+        // by special 0 value).
+        Os.bind(s, InetAddress.getByAddress(null, new byte[] {0, 0, 0, 0}), 0);
+        // Set backlog to 0 so connections end up stuck waiting to connect().
+        Os.listen(s, 0);
+
+        // Make URL pointing at this local port, where requests will get stuck connecting.
+        String url = "http://localhost:" + ((InetSocketAddress) Os.getsockname(s)).getPort();
+
+        // Launch a few requests at this local port.  Four seems to be the magic number where
+        // that request and any further request get stuck connecting.
+        TestUrlRequestCallback callback = null;
+        UrlRequest request = null;
+        for (int i = 0; i < 4; i++) {

[kapishnikov, 2016/10/20 17:25:46]

Why do we need 4 requests? Do we care about the fate of the first three
requests? 

[pauljensen, 2016/10/21 02:27:33]

We just need to fill up the connect queue.  I try to set the queue length to 0
in the listen() call above, but as I say in my comment on line 56, for whatever
reason it takes four requests before the queue overflows.  I think the linux
kernel interprets the backlog value how it pleases, I'm told a value of 1
actually results in a queue of more than 1 depending on your kernel version...
No, they're just filling the connect queue.

+            callback = new TestUrlRequestCallback();
+            request = new UrlRequest

[kapishnikov, 2016/10/20 17:25:46]

Use mCronetEngine.newUrlRequestBuilder(...)

[pauljensen, 2016/10/24 18:52:53]

Done.

+                              .Builder(url, callback, callback.getExecutor(),
+                                      testFramework.mCronetEngine)
+                              .build();
+            request.start();
+        }
+
+        // Wait for request to get to connecting stage
+        final AtomicBoolean requestConnecting = new AtomicBoolean();
+        while (!requestConnecting.get()) {
+            request.getStatus(new UrlRequest.StatusListener() {
+                @Override
+                public void onStatus(int status) {
+                    requestConnecting.set(status == UrlRequest.Status.CONNECTING);
+                }
+            });
+            Thread.sleep(100);
+        }
+
+        // Simulate network change which should abort connect jobs
+        ThreadUtils.postOnUiThread(new Runnable() {
+            @Override
+            public void run() {
+                NetworkChangeNotifier.getInstance().notifyObserversOfConnectionTypeChange(
+                        ConnectionType.CONNECTION_4G);
+            }
+        });
+
+        // Wait for ERR_NETWORK_CHANGED
+        callback.blockForDone();
+        assertNotNull(callback.mError);
+        assertTrue(callback.mOnErrorCalled);
+        assertEquals(-21, callback.mError.getCronetInternalErrorCode());

[kapishnikov, 2016/10/20 17:25:46]

-21 => NetError.ERR_NETWORK_CHANGED

[pauljensen, 2016/10/24 18:52:53]

Done.

+        assertEquals("Exception in CronetUrlRequest: net::ERR_NETWORK_CHANGED",
+                callback.mError.getMessage());
     }
 }