Convert WebView Layout test to JUnit4

android_webview/tools/system_webview_shell/BUILD.gn

Index: android_webview/tools/system_webview_shell/BUILD.gn
diff --git a/android_webview/tools/system_webview_shell/BUILD.gn b/android_webview/tools/system_webview_shell/BUILD.gn
index a3a54563296de47615b47e47e100b9a774150c6b..e79f5e79a67a92e31a3f4a061834771162026d8a 100644
--- a/android_webview/tools/system_webview_shell/BUILD.gn
+++ b/android_webview/tools/system_webview_shell/BUILD.gn
@@ -65,14 +65,15 @@ instrumentation_test_apk("system_webview_shell_layout_test_apk") {
   android_manifest = "layout_tests/AndroidManifest.xml"
   java_files = [
     "layout_tests/src/org/chromium/webview_shell/test/WebViewLayoutTest.java",
-    "layout_tests/src/org/chromium/webview_shell/test/WebViewLayoutTestRunner.java",
     "layout_tests/src/org/chromium/webview_shell/test/WebViewThreadTest.java",
   ]
   deps = [
     "//base:base_java",
     "//base:base_java_test_support",
     "//testing/android/reporter:reporter_java",
+    "//third_party/android_support_test_runner:rules_java",
     "//third_party/android_support_test_runner:runner_java",
+    "//third_party/junit",
   ]
   data = [
     "test/data/",