Initialize CommandLine for JUnit4 Tests

In JUnit3, CommandLine is initialized before a test run, we should do
the same to avoid test flakiness.

Bug: 640116
Change-Id: If9ac3945680060125cfc86b63cf79a91e21d13dc
Reviewed-on: https://chromium-review.googlesource.com/685811Reviewed-by: Bo <boliu@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Yoland Yan <yolandyan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#505868}

base/test/android/javatests/src/org/chromium/base/test/BaseJUnit4ClassRunner.java

@@ -18,6 +18,7 @@ import org.junit.runners.model.InitializationError;
 import org.junit.runners.model.Statement;
 
 import org.chromium.base.CollectionUtil;
+import org.chromium.base.CommandLine;
 import org.chromium.base.test.BaseTestResult.PreTestHook;
 import org.chromium.base.test.util.DisableIfSkipCheck;
 import org.chromium.base.test.util.MinAndroidSdkLevelSkipCheck;
@@ -161,10 +162,18 @@ public class BaseJUnit4ClassRunner extends AndroidJUnit4ClassRunner {
                 notifier.fireTestFinished(child);
             }
         } else {
+            initCommandLineForTest();
             super.run(notifier);
         }
     }
 
+    /**
+     * Override this method to change how test class runner initiate commandline flags
+     */
+    protected void initCommandLineForTest() {
+        CommandLine.init(null);
+    }
+
     @Override
     protected void runChild(FrameworkMethod method, RunNotifier notifier) {
         String testName = method.getName();

chrome/test/android/javatests/src/org/chromium/chrome/test/ChromeJUnit4ClassRunner.java

@@ -8,6 +8,7 @@ import android.support.test.InstrumentationRegistry;
 
 import org.junit.runners.model.InitializationError;
 
+import org.chromium.base.BaseChromiumApplication;
 import org.chromium.base.CollectionUtil;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
 import org.chromium.base.test.BaseTestResult.PreTestHook;
@@ -46,4 +47,8 @@ public class ChromeJUnit4ClassRunner extends BaseJUnit4ClassRunner {
                 new ChildProcessAllocatorSettingsHook(), Policies.getRegistrationHook());
     }
 
+    @Override
+    protected void initCommandLineForTest() {
+        BaseChromiumApplication.initCommandLine(InstrumentationRegistry.getTargetContext());
+    }
 }

content/public/test/android/javatests/src/org/chromium/content/browser/test/ContentJUnit4ClassRunner.java

@@ -8,6 +8,7 @@ import android.support.test.InstrumentationRegistry;
 
 import org.junit.runners.model.InitializationError;
 
+import org.chromium.base.BaseChromiumApplication;
 import org.chromium.base.CollectionUtil;
 import org.chromium.base.CommandLine;
 import org.chromium.base.test.BaseJUnit4ClassRunner;
@@ -47,4 +48,9 @@ public class ContentJUnit4ClassRunner extends BaseJUnit4ClassRunner {
             CommandLineFlags.getRegistrationHook(),
             new ChildProcessAllocatorSettingsHook()});
     }
+
+    @Override
+    protected void initCommandLineForTest() {
+        BaseChromiumApplication.initCommandLine(InstrumentationRegistry.getTargetContext());
+    }
 }