Fixes for -Wunused-function on Linux, Android and ChromeOS

chrome/browser/process_singleton_linux_unittest.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 "chrome/browser/process_singleton.h"
 
 #include <signal.h>
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <unistd.h>
@@ skipping 13 matching lines @@
 #include "base/threading/thread.h"
 #include "chrome/common/chrome_constants.h"
 #include "content/public/test/test_browser_thread.h"
 #include "net/base/net_util.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 using content::BrowserThread;
 
 namespace {
 
-bool NotificationCallback(const CommandLine& command_line,
-                          const base::FilePath& current_directory) {
-  return true;
-}
-
 class ProcessSingletonLinuxTest : public testing::Test {
  public:
   // A ProcessSingleton exposing some protected methods for testing.
   class TestableProcessSingleton : public ProcessSingleton {
    public:
     explicit TestableProcessSingleton(const base::FilePath& user_data_dir)
         : ProcessSingleton(
             user_data_dir,
             base::Bind(&TestableProcessSingleton::NotificationCallback,
                        base::Unretained(this))) {}
@@ skipping 340 matching lines @@
 
   // Also change the hostname, so the remote does not retry.
   EXPECT_EQ(0, unlink(lock_path_.value().c_str()));
   EXPECT_EQ(0, symlink("FAKEFOOHOST-1234", lock_path_.value().c_str()));
 
   std::string url("about:blank");
   EXPECT_EQ(ProcessSingleton::PROFILE_IN_USE,
             NotifyOtherProcessOrCreate(url, TestTimeouts::action_timeout()));
 }