[Fuchsia] Workaround netstack bug in RemoteDebuggingPort test

The test is trying to verify that WebEngine closes devtools port as
expected. It was using URLFetcher to make an HTTP request to devtools.
Due to a netstack bug (fxb/49779) sometimes that request was hanging
indefinitely, so the test was timing out. Updated the tests to connect
raw socket, which allows to verify that the port is closed without
hitting that netstack bug.

Bug: 1067727
Change-Id: Id07eefe490ca4e25cf6d9143636802f8115cd0db
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2143380Reviewed-by: Fabrice de Gans-Riberi <fdegans@chromium.org>
Commit-Queue: Sergey Ulanov <sergeyu@chromium.org>
Auto-Submit: Sergey Ulanov <sergeyu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#757920}

fuchsia/engine/web_engine_integration_test.cc

@@ -27,7 +27,9 @@
 #include "fuchsia/base/test_navigation_listener.h"
 #include "media/base/media_switches.h"
 #include "media/fuchsia/audio/fake_audio_consumer.h"
+#include "net/base/test_completion_callback.h"
 #include "net/http/http_request_headers.h"
+#include "net/socket/tcp_client_socket.h"
 #include "net/test/embedded_test_server/default_handlers.h"
 #include "net/test/embedded_test_server/embedded_test_server.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ -263,8 +265,7 @@ TEST_F(WebEngineIntegrationTest, InvalidUserAgent) {
 // Check that if the CreateContextParams has |remote_debugging_port| set then:
 // - DevTools becomes available when the first debuggable Frame is created.
 // - DevTools closes when the last debuggable Frame is closed.
-// Test is flaky. http://crbug.com/1067727
-TEST_F(WebEngineIntegrationTest, DISABLED_RemoteDebuggingPort) {
+TEST_F(WebEngineIntegrationTest, RemoteDebuggingPort) {
   StartWebEngine();
 
   // Create a Context with remote debugging enabled via an ephemeral port.
@@ -356,8 +357,32 @@ TEST_F(WebEngineIntegrationTest, DISABLED_RemoteDebuggingPort) {
   // handled the Frame tear down.
   controller_run_loop.Run();
 
-  devtools_list = cr_fuchsia::GetDevToolsListFromPort(remote_debugging_port);
-  EXPECT_TRUE(devtools_list.is_none());
+  // Verify that devtools server is shut down properly. WebEngine may shutdown
+  // the socket after shutting down the Frame, so make several attempts to
+  // connect until it fails. Don't try to read or write from/to the socket to
+  // avoid fxb/49779.
+  bool failed_to_connect = false;
+  for (int i = 0; i < 10; ++i) {
+    net::TestCompletionCallback connect_callback;
+    net::TCPClientSocket connecting_socket(
+        net::AddressList(net::IPEndPoint(net::IPAddress::IPv4Localhost(),
+                                         remote_debugging_port)),
+        nullptr, nullptr, net::NetLogSource());
+    int connect_result = connecting_socket.Connect(connect_callback.callback());
+    connect_result = connect_callback.GetResult(connect_result);
+
+    if (connect_result == net::OK) {
+      // If Connect() succeeded then try again a bit later.
+      base::PlatformThread::Sleep(base::TimeDelta::FromMilliseconds(10));
+      continue;
+    }
+
+    EXPECT_EQ(connect_result, net::ERR_CONNECTION_REFUSED);
+    failed_to_connect = true;
+    break;
+  }
+
+  EXPECT_TRUE(failed_to_connect);
 }
 
 // Check that remote debugging requests for Frames in non-debuggable Contexts