GTTF: Make it possible to pass sharding settings from command line.

base/test/test_switches.cc

 // Copyright (c) 2012 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.
 
 #include "base/test/test_switches.h"
 
 // Time (in milliseconds) that the tests should wait before timing out.
 // TODO(phajdan.jr): Clean up the switch names.
 const char switches::kTestLargeTimeout[] = "test-large-timeout";
 
 // Maximum number of tests to run in a single batch.
 const char switches::kTestLauncherBatchLimit[] = "test-launcher-batch-limit";
 
 // Number of parallel test launcher jobs.
 const char switches::kTestLauncherJobs[] = "test-launcher-jobs";
 
 // Path to test results file in our custom test launcher format.
 const char switches::kTestLauncherOutput[] = "test-launcher-output";
 
 // Path to test results file with all the info from the test launcher.
 const char switches::kTestLauncherSummaryOutput[] =
     "test-launcher-summary-output";
 
 // Flag controlling when test stdio is displayed as part of the launcher's
 // standard output.
 const char switches::kTestLauncherPrintTestStdio[] =
     "test-launcher-print-test-stdio";
 
+// Index of the test shard to run, starting from 0 (first shard) to total shards
+// minus one (last shard).
+const char switches::kTestLauncherShardIndex[] =
+    "test-launcher-shard-index";
+
+// Total number of shards. Must be the same for all shards.
+const char switches::kTestLauncherTotalShards[] =
+    "test-launcher-total-shards";
+
 // Time (in milliseconds) that the tests should wait before timing out.
 const char switches::kTestLauncherTimeout[] = "test-launcher-timeout";
 // TODO(phajdan.jr): Clean up the switch names.
 const char switches::kTestTinyTimeout[] = "test-tiny-timeout";
 const char switches::kUiTestActionTimeout[] = "ui-test-action-timeout";
 const char switches::kUiTestActionMaxTimeout[] = "ui-test-action-max-timeout";