Update from https://crrev.com/312398

base/test/launcher/test_launcher_ios.cc

 // 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.
 
 #include "base/test/launcher/test_launcher.h"
 
 #include "base/at_exit.h"
+#include "base/base_paths.h"
 #include "base/bind.h"
+#include "base/command_line.h"
+#include "base/files/file_path.h"
+#include "base/files/file_util.h"
+#include "base/files/scoped_temp_dir.h"
+#include "base/format_macros.h"
+#include "base/message_loop/message_loop.h"
+#include "base/path_service.h"
+#include "base/process/launch.h"
 #include "base/test/launcher/unit_test_launcher.h"
+#include "base/test/test_switches.h"
+#include "base/test/test_timeouts.h"
 
 namespace {
 
-int DummyRunTestSuite(void) {
-  return -1;
+const char kHelpFlag[] = "help";
+
+void PrintUsage() {
+  fprintf(stdout,
+          "Runs tests using the gtest framework, each batch of tests being\n"
+          "run in their own process. Supported command-line flags:\n"
+          "\n"
+          " Common flags:\n"
+          "  --gtest_filter=...\n"
+          "    Runs a subset of tests (see --gtest_help for more info).\n"
+          "\n"
+          "  --help\n"
+          "    Shows this message.\n"
+          "\n"
+          " Other flags:\n"
+          "  --test-launcher-retry-limit=N\n"
+          "    Sets the limit of test retries on failures to N.\n"
+          "\n"
+          "  --test-launcher-summary-output=PATH\n"
+          "    Saves a JSON machine-readable summary of the run.\n"
+          "\n"
+          "  --test-launcher-print-test-stdio=auto|always|never\n"
+          "    Controls when full test output is printed.\n"
+          "    auto means to print it when the test failed.\n"
+          "\n"
+          "  --test-launcher-total-shards=N\n"
+          "    Sets the total number of shards to N.\n"
+          "\n"
+          "  --test-launcher-shard-index=N\n"
+          "    Sets the shard index to run to N (from 0 to TOTAL - 1).\n");
+  fflush(stdout);
 }
 
+class IOSUnitTestLauncherDelegate : public base::UnitTestLauncherDelegate {
+ public:
+  IOSUnitTestLauncherDelegate() : base::UnitTestLauncherDelegate(0, false) {
+  }
+
+  bool Init() WARN_UNUSED_RESULT {
+    if (!PathService::Get(base::DIR_EXE, &dir_exe_)) {
+      LOG(ERROR) << "Failed to get directory of current executable.";
+      return false;
+    }
+
+    base::CommandLine* command_line = base::CommandLine::ForCurrentProcess();
+    std::vector<std::string> args(command_line->GetArgs());
+    if (args.size() < 1) {
+      LOG(ERROR) << "Arguments expected.";
+      return false;
+    }
+    test_name_ = args[0];
+
+    base::CommandLine cmd_line(dir_exe_.AppendASCII(test_name_ + ".app"));
+    cmd_line.AppendSwitch(switches::kTestLauncherPrintWritablePath);
+    cmd_line.PrependWrapper(dir_exe_.AppendASCII("iossim").value());
+
+    std::string raw_output;
+    if (!base::GetAppOutput(cmd_line, &raw_output)) {
+      LOG(ERROR) << "GetAppOutput failed.";
+      return false;
+    }
+    writable_path_ = base::FilePath(raw_output);
+
+    return true;
+  }
+
+  bool GetTests(std::vector<base::SplitTestName>* output) override {
+    base::ScopedTempDir temp_dir;
+    if (!temp_dir.CreateUniqueTempDirUnderPath(writable_path_))
+      return false;
+    base::FilePath test_list_path(
+        temp_dir.path().AppendASCII("test_list.json"));
+
+    base::CommandLine cmd_line(dir_exe_.AppendASCII(test_name_ + ".app"));
+    cmd_line.AppendSwitchPath(switches::kTestLauncherListTests, test_list_path);
+    cmd_line.PrependWrapper(dir_exe_.AppendASCII("iossim").value());
+
+    base::LaunchOptions launch_options;
+    launch_options.wait = true;
+
+    if (!base::LaunchProcess(cmd_line, launch_options).IsValid())
+      return false;
+
+    return base::ReadTestNamesFromFile(test_list_path, output);
+  }
+
+ private:
+  // Directory containing test launcher's executable.
+  base::FilePath dir_exe_;
+
+  // Name of the test executable to run.
+  std::string test_name_;
+
+  // Path that launched test binary can write to.
+  base::FilePath writable_path_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOSUnitTestLauncherDelegate);
+};
+
 }  // namespace
 
 int main(int argc, char** argv) {
   base::AtExitManager at_exit;
-  return base::LaunchUnitTests(argc, argv, base::Bind(&DummyRunTestSuite));
+
+  base::CommandLine::Init(argc, argv);
+
+  if (base::CommandLine::ForCurrentProcess()->HasSwitch(kHelpFlag)) {
+    PrintUsage();
+    return 0;
+  }
+
+  base::TimeTicks start_time(base::TimeTicks::Now());
+
+  TestTimeouts::Initialize();
+
+  base::MessageLoopForIO message_loop;
+
+  IOSUnitTestLauncherDelegate delegate;
+  if (!delegate.Init()) {
+    fprintf(stderr, "Failed to intialize test launcher delegate.\n");
+    fflush(stderr);
+    return 1;
+  }
+  // Force one job since we can't run multiple simulators in parallel.
+  base::TestLauncher launcher(&delegate, 1);
+  bool success = launcher.Run();
+
+  fprintf(stdout, "Tests took %" PRId64 " seconds.\n",
+          (base::TimeTicks::Now() - start_time).InSeconds());
+  fflush(stdout);
+
+  return (success ? 0 : 1);
 }