Added histograms on process singleton create when remote process exists and we cannot notify it

chrome/browser/process_singleton_posix_unittest.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 "chrome/browser/process_singleton.h"
 
 #include <fcntl.h>
 #include <limits.h>
 #include <signal.h>
 #include <stddef.h>
 #include <sys/types.h>
 #include <sys/un.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #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/location.h"
 #include "base/posix/eintr_wrapper.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/waitable_event.h"
+#include "base/test/histogram_tester.h"
 #include "base/test/test_timeouts.h"
 #include "base/test/thread_test_helper.h"
 #include "base/threading/thread.h"
 #include "build/build_config.h"
 #include "chrome/common/chrome_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/test/test_browser_thread_bundle.h"
 #include "net/base/network_interfaces.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
@@ skipping 239 matching lines @@
 // TODO(james.su@gmail.com): port following tests to Windows.
 // Test success case of NotifyOtherProcess().
 TEST_F(ProcessSingletonPosixTest, NotifyOtherProcessSuccess) {
   CreateProcessSingletonOnThread();
   EXPECT_EQ(ProcessSingleton::PROCESS_NOTIFIED, NotifyOtherProcess(true));
   CheckNotified();
 }
 
 // Test failure case of NotifyOtherProcess().
 TEST_F(ProcessSingletonPosixTest, NotifyOtherProcessFailure) {
+  base::HistogramTester histogram_tester;
   CreateProcessSingletonOnThread();
 
   BlockWorkerThread();
   EXPECT_EQ(ProcessSingleton::PROCESS_NONE, NotifyOtherProcess(true));
   ASSERT_EQ(1, kill_callbacks_);
   UnblockWorkerThread();
+  histogram_tester.ExpectUniqueSample(
+      "Chrome.ProcessSingleton.RemoteHungProcessTerminateReason",
+      ProcessSingleton::SOCKET_READ_FAILED, 1u);
 }
 
 // Test that we don't kill ourselves by accident if a lockfile with the same pid
 // happens to exist.
 TEST_F(ProcessSingletonPosixTest, NotifyOtherProcessNoSuicide) {
   CreateProcessSingletonOnThread();
   // Replace lockfile with one containing our own pid.
   EXPECT_EQ(0, unlink(lock_path_.value().c_str()));
   std::string symlink_content = base::StringPrintf(
       "%s%c%u",
@@ skipping 139 matching lines @@
 // Test that if there is an existing lock file, and it's not locked, we replace
 // it.
 TEST_F(ProcessSingletonPosixTest, CreateReplacesOldMacLock) {
   std::unique_ptr<TestableProcessSingleton> process_singleton(
       CreateProcessSingleton());
   EXPECT_EQ(0, base::WriteFile(lock_path_, "", 0));
   EXPECT_TRUE(process_singleton->Create());
   VerifyFiles();
 }
 #endif  // defined(OS_MACOSX)