Use --gtest_flagfile for --gtest_filter in unit test launcher

base/test/launcher/test_launcher.h

 // Copyright 2013 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.
 
 #ifndef BASE_TEST_LAUNCHER_TEST_LAUNCHER_H_
 #define BASE_TEST_LAUNCHER_TEST_LAUNCHER_H_
 
 #include <set>
 #include <string>
 
@@ skipping 13 matching lines @@
 
 namespace base {
 
 class CommandLine;
 struct LaunchOptions;
 class SequencedWorkerPoolOwner;
 class TestLauncher;
 
 // Constants for GTest command-line flags.
 extern const char kGTestFilterFlag[];
+extern const char kGTestFlagfileFlag[];
 extern const char kGTestHelpFlag[];
 extern const char kGTestListTestsFlag[];
 extern const char kGTestRepeatFlag[];
 extern const char kGTestRunDisabledTestsFlag[];
 extern const char kGTestOutputFlag[];
 
 // Interface for use with LaunchTests that abstracts away exact details
 // which tests and how are run.
 class TestLauncherDelegate {
  public:
@@ skipping 161 matching lines @@
   DISALLOW_COPY_AND_ASSIGN(TestLauncher);
 };
 
 // Extract part from |full_output| that applies to |result|.
 std::string GetTestOutputSnippet(const TestResult& result,
                                  const std::string& full_output);
 
 }  // namespace base
 
 #endif  // BASE_TEST_LAUNCHER_TEST_LAUNCHER_H_