Delete the utility process startup ping.

chrome/common/chrome_utility_messages.h

 // 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.
 
 // Multiply-included message file, so no include guard.
 
 #if defined(OS_WIN)
 #include <Windows.h>
 #endif  // defined(OS_WIN)
 
@@ skipping 146 matching lines @@
                      base::FilePath /* output_file */)
 
 #if defined(OS_CHROMEOS)
 // Tell the utility process to create a zip file on the given list of files.
 IPC_MESSAGE_CONTROL3(ChromeUtilityMsg_CreateZipFile,
                      base::FilePath /* src_dir */,
                      std::vector<base::FilePath> /* src_relative_paths */,
                      base::FileDescriptor /* dest_fd */)
 #endif  // defined(OS_CHROMEOS)
 
-// Requests the utility process to respond with a
-// ChromeUtilityHostMsg_ProcessStarted message once it has started.  This may
-// be used if the host process needs a handle to the running utility process.
-IPC_MESSAGE_CONTROL0(ChromeUtilityMsg_StartupPing)

[Lei Zhang, 2016/04/13 04:39:36]

And you need an IPC reviewer.

-
 #if defined(FULL_SAFE_BROWSING)
 // Tells the utility process to analyze a zip file for malicious download
 // protection, providing a file that can be used temporarily to analyze binaries
 // contained therein.
 IPC_MESSAGE_CONTROL2(ChromeUtilityMsg_AnalyzeZipFileForDownloadProtection,
                      IPC::PlatformFileForTransit /* zip_file */,
                      IPC::PlatformFileForTransit /* temp_file */)
 
 #if defined(OS_MACOSX)
 // Tells the utility process to analyze a DMG file for malicious download
@@ skipping 44 matching lines @@
 IPC_MESSAGE_CONTROL1(ChromeUtilityHostMsg_PatchFile_Finished, int /* result */)
 
 #if defined(OS_CHROMEOS)
 // Reply when the utility process has succeeded in creating the zip file.
 IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_CreateZipFile_Succeeded)
 
 // Reply when an error occured in creating the zip file.
 IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_CreateZipFile_Failed)
 #endif  // defined(OS_CHROMEOS)
 
-// Reply when the utility process has started.
-IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_ProcessStarted)
-
 #if defined(FULL_SAFE_BROWSING)
 // Reply when a zip file has been analyzed for malicious download protection.
 IPC_MESSAGE_CONTROL1(
     ChromeUtilityHostMsg_AnalyzeZipFileForDownloadProtection_Finished,
     safe_browsing::zip_analyzer::Results)
 
 #if defined(OS_MACOSX)
 // Reply when a DMG file has been analyzed for malicious download protection.
 IPC_MESSAGE_CONTROL1(
     ChromeUtilityHostMsg_AnalyzeDmgFileForDownloadProtection_Finished,
     safe_browsing::zip_analyzer::Results)
 #endif  // defined(OS_MACOSX)
 #endif  // defined(FULL_SAFE_BROWSING)
 
 #if defined(OS_WIN)
 IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_GetOpenFileName_Failed)
 IPC_MESSAGE_CONTROL2(ChromeUtilityHostMsg_GetOpenFileName_Result,
                      base::FilePath /* directory */,
                      std::vector<base::FilePath> /* filenames */)
 IPC_MESSAGE_CONTROL0(ChromeUtilityHostMsg_GetSaveFileName_Failed)
 IPC_MESSAGE_CONTROL2(ChromeUtilityHostMsg_GetSaveFileName_Result,
                      base::FilePath /* path */,
                      int /* one_based_filter_index  */)
 #endif  // defined(OS_WIN)