Android GTest Runner: Create flags & test list files only when required

testing/android/native_test/java/src/org/chromium/native_test/NativeTestInstrumentationTestRunner.java

 // Copyright 2014 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.native_test;
 
 import android.app.Activity;
 import android.app.ActivityManager;
 import android.app.Instrumentation;
 import android.content.ComponentName;
@@ skipping 33 matching lines @@
 public class NativeTestInstrumentationTestRunner extends Instrumentation {
 
     public static final String EXTRA_NATIVE_TEST_ACTIVITY =
             "org.chromium.native_test.NativeTestInstrumentationTestRunner.NativeTestActivity";
     public static final String EXTRA_SHARD_NANO_TIMEOUT =
             "org.chromium.native_test.NativeTestInstrumentationTestRunner.ShardNanoTimeout";
     public static final String EXTRA_SHARD_SIZE_LIMIT =
             "org.chromium.native_test.NativeTestInstrumentationTestRunner.ShardSizeLimit";
     public static final String EXTRA_TEST_LIST_FILE =
             "org.chromium.native_test.NativeTestInstrumentationTestRunner.TestList";
+    public static final String EXTRA_TEST =
+            "org.chromium.native_test.NativeTestInstrumentationTestRunner.Test";
 
     private static final String TAG = "cr_NativeTest";
 
     private static final long DEFAULT_SHARD_NANO_TIMEOUT = 60 * 1000000000L;
     // Default to no size limit.
     private static final int DEFAULT_SHARD_SIZE_LIMIT = 0;
     private static final String DEFAULT_NATIVE_TEST_ACTIVITY =
             "org.chromium.native_test.NativeUnitTestActivity";
     private static final Pattern RE_TEST_OUTPUT =
             Pattern.compile("\\[ *([^ ]*) *\\] ?([^ ]+)( .*)?$");
@@ skipping 21 matching lines @@
         mTransparentArguments.remove(EXTRA_NATIVE_TEST_ACTIVITY);
 
         String shardNanoTimeout = arguments.getString(EXTRA_SHARD_NANO_TIMEOUT);
         if (shardNanoTimeout != null) mShardNanoTimeout = Long.parseLong(shardNanoTimeout);
         mTransparentArguments.remove(EXTRA_SHARD_NANO_TIMEOUT);
 
         String shardSizeLimit = arguments.getString(EXTRA_SHARD_SIZE_LIMIT);
         if (shardSizeLimit != null) mShardSizeLimit = Integer.parseInt(shardSizeLimit);
         mTransparentArguments.remove(EXTRA_SHARD_SIZE_LIMIT);
 
+        String singleTest = arguments.getString(EXTRA_TEST);
+        if (singleTest != null) {
+            ArrayList<String> shard = new ArrayList<>(1);
+            shard.add(singleTest);
+            mShards.add(shard);
+        }
+
         String testListFilePath = arguments.getString(EXTRA_TEST_LIST_FILE);
         if (testListFilePath != null) {
             File testListFile = new File(testListFilePath);
             try {
                 BufferedReader testListFileReader =
                         new BufferedReader(new FileReader(testListFile));
 
                 String test;
                 ArrayList<String> workingShard = new ArrayList<String>();
                 while ((test = testListFileReader.readLine()) != null) {
@@ skipping 209 matching lines @@
             if (mStdoutFile != null) {
                 if (!mStdoutFile.delete()) {
                     Log.e(TAG, "Unable to delete %s", mStdoutFile.getAbsolutePath());
                 }
             }
         }
         return results;
     }
 
 }