[WebLayer] Add test-only AIDL + java tests.

Add a test-only AIDL for instrumentation tests, and add a simple
instrumentation test to verify that network change auto detect is on
when a weblayer activity is created.

The change to run weblayer_private_instrumentation_test_apk on clank
clank builders is here:
https://chrome-internal-review.googlesource.com/c/clank/internal/apps/+/2396452

Bug: 1018848, 1035912

Change-Id: I0bddd1f34e9b2ce4a222ae39aa34611d690fa44a
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1975886
Commit-Queue: Mugdha Lakhani <nator@chromium.org>
Reviewed-by: Clark DuVall <cduvall@chromium.org>
Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Cr-Commit-Position: refs/heads/master@{#730521}

PRESUBMIT.py

@@ -2859,6 +2859,8 @@ def _GetOwnersFilesToCheckForIpcOwners(input_api):
       # These files are just used to communicate between class loaders running
       # in the same process.
       'weblayer/browser/java/org/chromium/weblayer_private/interfaces/*',
+      'weblayer/browser/java/org/chromium/weblayer_private/test_interfaces/*',
+
   ]
 
   # Dictionary mapping an OWNERS file path to Patterns.

testing/buildbot/chromium.android.fyi.json

@@ -4765,6 +4765,64 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices",
+          "--avd-config=../../tools/android/avd/proto/generic_android23.textpb"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "device_os": null,
+              "device_type": null,
+              "os": "Ubuntu-16.04",
+              "pool": "chromium.tests.avd",
+              "ssd": "1"
+            }
+          ],
+          "named_caches": [
+            {
+              "name": "avd_generic_android23",
+              "path": ".android"
+            },
+            {
+              "name": "system_images_android_23_google_apis_x86",
+              "path": ".emulator_sdk"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -9124,6 +9182,64 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices",
+          "--avd-config=../../tools/android/avd/proto/generic_android28.textpb"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "cpu": "x86-64",
+              "device_os": null,
+              "device_type": null,
+              "os": "Ubuntu-16.04",
+              "pool": "chromium.tests.avd",
+              "ssd": "1"
+            }
+          ],
+          "named_caches": [
+            {
+              "name": "avd_generic_android28",
+              "path": ".android"
+            },
+            {
+              "name": "system_images_android_28_google_apis_x86",
+              "path": ".emulator_sdk"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",

testing/buildbot/chromium.android.json

@@ -11205,6 +11205,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "LMY48I",
+              "device_os_type": "userdebug",
+              "device_type": "hammerhead",
+              "os": "Android"
+            }
+          ],
+          "expiration": 10800,
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -14398,6 +14444,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "LMY49B",
+              "device_os_type": "userdebug",
+              "device_type": "flo",
+              "os": "Android"
+            }
+          ],
+          "expiration": 10800,
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -17715,6 +17807,51 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "MMB29Q",
+              "device_os_type": "userdebug",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -20905,6 +21042,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "MRA58Z",
+              "device_os_type": "userdebug",
+              "device_type": "flo",
+              "os": "Android"
+            }
+          ],
+          "expiration": 10800,
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -25054,6 +25237,51 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "MMB29Q",
+              "device_os_type": "userdebug",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -32886,6 +33114,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "isolate_coverage_data": true,
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "MMB29Q",
+              "device_os_type": "userdebug",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",
@@ -36839,6 +37113,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "PQ3A.190801.002",
+              "device_os_flavor": "google",
+              "device_os_type": "userdebug",
+              "device_type": "walleye",
+              "os": "Android"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",

testing/buildbot/chromium.fyi.json

@@ -9221,6 +9221,52 @@
         "test": "weblayer_instrumentation_test_apk",
         "test_target": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk"
       },
+      {
+        "args": [
+          "--gs-results-bucket=chromium-result-details",
+          "--recover-devices"
+        ],
+        "isolate_coverage_data": true,
+        "merge": {
+          "args": [
+            "--bucket",
+            "chromium-result-details",
+            "--test-name",
+            "weblayer_private_instrumentation_test_apk"
+          ],
+          "script": "//build/android/pylib/results/presentation/test_results_presentation.py"
+        },
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "cipd_packages": [
+            {
+              "cipd_package": "infra/tools/luci/logdog/butler/${platform}",
+              "location": "bin",
+              "revision": "git_revision:ff387eadf445b24c935f1cf7d6ddd279f8a6b04c"
+            }
+          ],
+          "dimension_sets": [
+            {
+              "device_os": "MMB29Q",
+              "device_os_type": "userdebug",
+              "device_type": "bullhead",
+              "os": "Android"
+            }
+          ],
+          "output_links": [
+            {
+              "link": [
+                "https://luci-logdog.appspot.com/v/?s",
+                "=android%2Fswarming%2Flogcats%2F",
+                "${TASK_ID}%2F%2B%2Funified_logcats"
+              ],
+              "name": "shard #${SHARD_INDEX} logcats"
+            }
+          ]
+        },
+        "test": "weblayer_private_instrumentation_test_apk",
+        "test_target": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk"
+      },
       {
         "args": [
           "--gs-results-bucket=chromium-result-details",

testing/buildbot/gn_isolate_map.pyl

@@ -1813,6 +1813,10 @@
     "label": "//weblayer/browser/android/javatests:weblayer_instrumentation_test_apk",
     "type": "console_test_launcher",
   },
+  "weblayer_private_instrumentation_test_apk": {
+    "label": "//weblayer/browser/android/javatests:weblayer_private_instrumentation_test_apk",
+    "type": "console_test_launcher",
+  },
   "weblayer_shell": {
     "label": "//weblayer/shell/android:run_weblayer_shell",
     "type": "additional_compile_target",

testing/buildbot/test_suites.pyl

@@ -3243,6 +3243,8 @@
     'weblayer_android_gtests': {
       'weblayer_instrumentation_test_apk': {
       },
+      'weblayer_private_instrumentation_test_apk': {
+      },
     },
 
     'weblayer_gtests': {

weblayer/browser/android/javatests/AndroidManifest.xml

@@ -9,6 +9,7 @@
 <manifest xmlns:android="http://schemas.android.com/apk/res/android"
     package="org.chromium.weblayer.tests">
   <uses-permission android:name="android.permission.RUN_INSTRUMENTATION" />
+  <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>
   <!-- We add an application tag here just so that we can indicate that this
        package needs to link against the android.test library, which is
        needed when building test cases. -->

weblayer/browser/android/javatests/BUILD.gn

@@ -49,15 +49,36 @@ android_library("weblayer_java_tests") {
   ]
 }
 
+android_library("weblayer_private_java_tests") {
+  testonly = true
+  sources = [
+    "src/org/chromium/weblayer/test/InstrumentationActivityTestRule.java",
+    "src/org/chromium/weblayer/test/NavigationWaiter.java",
+    "src/org/chromium/weblayer/test/NetworkChangeNotifierTest.java",
+    "src/org/chromium/weblayer/test/WebLayerJUnit4ClassRunner.java",
+  ]
+  deps = [
+    "//base:base_java",
+    "//base:base_java_test_support",
+    "//content/public/test/android:content_java_test_support",
+    "//net/android:net_java_test_support",
+    "//third_party/android_deps:com_android_support_support_fragment_java",
+    "//third_party/android_support_test_runner:rules_java",
+    "//third_party/android_support_test_runner:runner_java",
+    "//third_party/junit:junit",
+    "//weblayer/public/java",
+    "//weblayer/public/javatestutil:test_java",
+    "//weblayer/shell/android:weblayer_shell_java",
+  ]
+}
+
 template("weblayer_instrumentation") {
   instrumentation_test_apk(target_name) {
     forward_variables_from(invoker, "*")
 
     android_manifest = "AndroidManifest.xml"
     min_sdk_version = 21
-    deps = [
-      ":weblayer_java_tests",
-    ]
+
     if (!defined(additional_apks)) {
       additional_apks = []
     }
@@ -70,12 +91,16 @@ template("weblayer_instrumentation") {
 
 # Runs the instrumentation tests loading the implementation from the default
 # WebView provider. This is the loading path that is used in production.
-# TODO(cduvall): Figure out why the test infrastructure fails on some Android
-# versions.
+# TODO(crbug.com/1033070): Figure out why the test infrastructure fails on some
+# Android versions.
 weblayer_instrumentation("weblayer_instrumentation_test_apk") {
   apk_name = "WebLayerInstrumentationTest"
   apk_under_test = "//weblayer/shell/android:weblayer_shell_system_webview_apk"
   use_webview_provider = system_webview_apk_target
+
+  deps = [
+    ":weblayer_java_tests",
+  ]
 }
 
 # Runs the instrumentation tests loading the implementation from the WebLayer
@@ -84,4 +109,18 @@ weblayer_instrumentation("weblayer_support_instrumentation_test_apk") {
   apk_name = "WebLayerSupportInstrumentationTest"
   apk_under_test = "//weblayer/shell/android:weblayer_shell_apk"
   additional_apks = [ "//weblayer/shell/android:weblayer_support_apk" ]
+
+  deps = [
+    ":weblayer_java_tests",
+  ]
+}
+
+weblayer_instrumentation("weblayer_private_instrumentation_test_apk") {
+  apk_name = "WebLayerPrivateInstrumentationTest"
+  apk_under_test = "//weblayer/shell/android:weblayer_shell_apk"
+  additional_apks = [ "//weblayer/shell/android:weblayer_support_apk" ]
+
+  deps = [
+    ":weblayer_private_java_tests",
+  ]
 }

weblayer/browser/android/javatests/src/org/chromium/weblayer/test/NetworkChangeNotifierTest.java

@@ -0,0 +1,38 @@
+// Copyright 2020 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.weblayer.test;
+
+import android.os.RemoteException;
+import android.support.test.filters.SmallTest;
+
+import org.json.JSONException;
+import org.junit.Assert;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import org.chromium.base.test.util.Feature;
+import org.chromium.weblayer.TestWebLayer;
+import org.chromium.weblayer.shell.InstrumentationActivity;
+
+/** Tests that integration with NetworkStateNotifier works as expected. */
+@RunWith(WebLayerJUnit4ClassRunner.class)
+public final class NetworkChangeNotifierTest {
+    @Rule
+    public InstrumentationActivityTestRule mActivityTestRule =
+            new InstrumentationActivityTestRule();
+
+    @Test
+    @SmallTest
+    @Feature({"WebLayer"})
+    public void testNetworkChangeNotifierAutoDetectRegistered()
+            throws RemoteException, JSONException {
+        // This creates an activity with WebLayer loaded, and causes WebLayer
+        // code to start listening to changes in network connectivity.
+        InstrumentationActivity activity = mActivityTestRule.launchShellWithUrl("about:blank");
+        TestWebLayer testWebLayer = TestWebLayer.getTestWebLayer(activity.getApplicationContext());
+        Assert.assertTrue(testWebLayer.isNetworkChangeAutoDetectOn());
+    }
+}

weblayer/browser/java/BUILD.gn

@@ -87,6 +87,17 @@ android_library("java") {
       "//third_party/android_sdk:public_framework_system_java"
 }
 
+android_library("test_java") {
+  testonly = true
+  sources = [
+    "org/chromium/weblayer_private/test/TestWebLayerImpl.java",
+  ]
+  deps = [
+    "//net/android:net_java",
+  ]
+  srcjar_deps = [ ":test_aidl" ]
+}
+
 generate_jni("jni") {
   sources = [
     "org/chromium/weblayer_private/ContentViewRenderView.java",
@@ -180,3 +191,11 @@ android_aidl("aidl") {
     "org/chromium/weblayer_private/interfaces/IWebLayerFactory.aidl",
   ]
 }
+
+android_aidl("test_aidl") {
+  import_include = [ "." ]
+  testonly = true
+  sources = [
+    "org/chromium/weblayer_private/test_interfaces/ITestWebLayer.aidl",
+  ]
+}

weblayer/browser/java/org/chromium/weblayer_private/test/TestWebLayerImpl.java

@@ -0,0 +1,29 @@
+// Copyright 2020 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.weblayer_private.test;
+
+import android.os.IBinder;
+
+import org.chromium.base.annotations.UsedByReflection;
+import org.chromium.net.NetworkChangeNotifier;
+import org.chromium.weblayer_private.test_interfaces.ITestWebLayer;
+
+/**
+ * Root implementation class for TestWebLayer.
+ */
+@UsedByReflection("WebLayer")
+public final class TestWebLayerImpl extends ITestWebLayer.Stub {
+    @UsedByReflection("WebLayer")
+    public static IBinder create() {
+        return new TestWebLayerImpl();
+    }
+
+    private TestWebLayerImpl() {}
+
+    @Override
+    public boolean isNetworkChangeAutoDetectOn() {
+        return NetworkChangeNotifier.getAutoDetectorForTest() != null;
+    }
+}

weblayer/browser/java/org/chromium/weblayer_private/test_interfaces/ITestWebLayer.aidl

@@ -0,0 +1,10 @@
+// Copyright 2020 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.weblayer_private.test_interfaces;
+
+interface ITestWebLayer {
+  // Force network connectivity state.
+  boolean isNetworkChangeAutoDetectOn() = 1;
+}

weblayer/public/javatestutil/BUILD.gn

@@ -0,0 +1,20 @@
+# Copyright 2020 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.
+
+import("//build/config/android/config.gni")
+import("//build/config/android/rules.gni")
+
+android_library("test_java") {
+  testonly = true
+  sources = [
+    "org/chromium/weblayer/TestWebLayer.java",
+  ]
+
+  deps = [
+    "//base:base_java_test_support",
+    "//third_party/junit:junit",
+    "//weblayer/browser/java:test_java",
+    "//weblayer/public/java",
+  ]
+}

weblayer/public/javatestutil/org/chromium/weblayer/TestWebLayer.java

@@ -0,0 +1,50 @@
+// Copyright 2020 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.weblayer;
+
+import android.content.Context;
+import android.content.pm.PackageManager;
+import android.os.IBinder;
+import android.os.RemoteException;
+import android.util.AndroidRuntimeException;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import org.chromium.weblayer_private.test_interfaces.ITestWebLayer;
+
+/**
+ * TestWebLayer is responsible for passing messages over a test only AIDL to the
+ * WebLayer implementation.
+ */
+public final class TestWebLayer {
+    @Nullable
+    private ITestWebLayer mITestWebLayer;
+
+    @Nullable
+    private static TestWebLayer sInstance;
+
+    public static TestWebLayer getTestWebLayer(@NonNull Context appContext) {
+        if (sInstance == null) sInstance = new TestWebLayer(appContext);
+        return sInstance;
+    }
+
+    private TestWebLayer(@NonNull Context appContext) {
+        ClassLoader remoteClassLoader;
+        try {
+            remoteClassLoader = WebLayer.getOrCreateRemoteContext(appContext).getClassLoader();
+            Class TestWebLayerClass = remoteClassLoader.loadClass(
+                    "org.chromium.weblayer_private.test.TestWebLayerImpl");
+            mITestWebLayer = ITestWebLayer.Stub.asInterface(
+                    (IBinder) TestWebLayerClass.getMethod("create").invoke(null));
+        } catch (PackageManager.NameNotFoundException | ReflectiveOperationException e) {
+            throw new AndroidRuntimeException(e);
+        }
+    }
+
+    public boolean isNetworkChangeAutoDetectOn() throws RemoteException {
+        return mITestWebLayer.isNetworkChangeAutoDetectOn();
+    }
+}

weblayer/shell/android/BUILD.gn

@@ -163,6 +163,7 @@ android_apk("weblayer_support_apk") {
     "//base:base_java",
     "//weblayer:locale_pak_assets",
     "//weblayer/browser/java",
+    "//weblayer/browser/java:test_java",
   ]
 
   # Transitive dependencies