Create ContentShellActivityTestRule and BaseJUnitRunner

content/shell/android/BUILD.gn

Index: content/shell/android/BUILD.gn
diff --git a/content/shell/android/BUILD.gn b/content/shell/android/BUILD.gn
index ad17f158843412128f41471dcb9708ab196bc814..a3c841675e878c7dbaa72fb49a6556685eaab64f 100644
--- a/content/shell/android/BUILD.gn
+++ b/content/shell/android/BUILD.gn
@@ -143,13 +143,16 @@ android_library("content_shell_test_java") {
     "//content/public/android:content_java",
     "//content/public/test/android:content_java_test_support",
     "//content/shell/android:content_shell_java",
+    "//third_party/android_support_test_runner:rules_java",
     "//third_party/android_support_test_runner:runner_java",
+    "//third_party/junit",
     "//ui/android:ui_java",
   ]
   java_files = [
     "javatests/src/org/chromium/content_shell_apk/ContentShellPreconditionsTest.java",
     "javatests/src/org/chromium/content_shell_apk/ContentShellShellManagementTest.java",
     "javatests/src/org/chromium/content_shell_apk/ContentShellTestBase.java",
+    "javatests/src/org/chromium/content_shell_apk/ContentShellActivityTestRule.java",
     "javatests/src/org/chromium/content_shell_apk/ContentShellUrlTest.java",
   ]
 }