Add TestRules for content shell test and refactor test bases

content/public/android/BUILD.gn

Index: content/public/android/BUILD.gn
diff --git a/content/public/android/BUILD.gn b/content/public/android/BUILD.gn
index e8a363c1e1f100cb49241204e52c29d245c3e304..90f76c251806ee5691e3a7c8d149a5d09b95258d 100644
--- a/content/public/android/BUILD.gn
+++ b/content/public/android/BUILD.gn
@@ -381,8 +381,10 @@ android_library("content_javatests") {
     "//mojo/public/java:system_java",
     "//net/android:net_java",
     "//net/android:net_java_test_support",
+    "//third_party/android_support_test_runner:rules_java",
     "//third_party/android_support_test_runner:runner_java",
     "//third_party/android_tools:legacy_http_javalib",
+    "//third_party/junit",
     "//ui/android:ui_java",
   ]
 
@@ -394,6 +396,8 @@ android_library("content_javatests") {
     "javatests/src/org/chromium/content/browser/ClipboardTest.java",
     "javatests/src/org/chromium/content/browser/ContentCommandLineTest.java",
     "javatests/src/org/chromium/content/browser/ContentDetectionTestBase.java",
+    "javatests/src/org/chromium/content/browser/ContentDetectionActivityTestRule.java",
+    "javatests/src/org/chromium/content/browser/ContentDetectionTestCommon.java",
     "javatests/src/org/chromium/content/browser/ContentViewCoreSelectionTest.java",
     "javatests/src/org/chromium/content/browser/ContentViewLocationTest.java",
     "javatests/src/org/chromium/content/browser/ContentViewPopupZoomerTest.java",
@@ -404,6 +408,7 @@ android_library("content_javatests") {
     "javatests/src/org/chromium/content/browser/GestureDetectorResetTest.java",
     "javatests/src/org/chromium/content/browser/ImportantFileWriterAndroidTest.java",
     "javatests/src/org/chromium/content/browser/InterstitialPageTest.java",
+    "javatests/src/org/chromium/content/browser/JavaBridgeActivityTestRule.java",
     "javatests/src/org/chromium/content/browser/JavaBridgeArrayCoercionTest.java",
     "javatests/src/org/chromium/content/browser/JavaBridgeArrayTest.java",
     "javatests/src/org/chromium/content/browser/JavaBridgeBareboneTest.java",
@@ -413,6 +418,7 @@ android_library("content_javatests") {
     "javatests/src/org/chromium/content/browser/JavaBridgeFieldsTest.java",
     "javatests/src/org/chromium/content/browser/JavaBridgeReturnValuesTest.java",
     "javatests/src/org/chromium/content/browser/JavaBridgeTestBase.java",
+    "javatests/src/org/chromium/content/browser/JavaBridgeTestCommon.java",
     "javatests/src/org/chromium/content/browser/LocationProviderTest.java",
     "javatests/src/org/chromium/content/browser/MediaResourceGetterTest.java",
     "javatests/src/org/chromium/content/browser/MediaSessionTest.java",