Use PathService in installer::GetModulePath().

chrome/installer/util/module_util_win.cc

 // Copyright (c) 2015 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 <windows.h>
-
 #include "chrome/installer/util/module_util_win.h"
 
+#include "base/base_paths.h"
 #include "base/file_version_info.h"
 #include "base/files/file.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
+#include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/version.h"
 
 namespace installer {
 
 namespace {
 
-// Returns the directory in which the currently running executable resides.
-base::FilePath GetExecutableDir() {
-  base::char16 path[MAX_PATH];
-  ::GetModuleFileNameW(nullptr, path, MAX_PATH);
-  return base::FilePath(path).DirName();
-}
-
 // Returns the version in the current module's version resource or the empty
 // string if none found.
 base::string16 GetCurrentModuleVersion() {
   scoped_ptr<FileVersionInfo> file_version_info(
       CREATE_FILE_VERSION_INFO_FOR_CURRENT_MODULE());
   if (file_version_info.get()) {
     base::string16 version_string(file_version_info->file_version());
-    if (Version(base::UTF16ToASCII(version_string)).IsValid())
+    if (base::Version(base::UTF16ToASCII(version_string)).IsValid())
       return version_string;
   }
   return base::string16();
 }
 
 // Indicates whether a file can be opened using the same flags that
 // ::LoadLibrary() uses to open modules.
 bool ModuleCanBeRead(const base::FilePath file_path) {
   return base::File(file_path, base::File::FLAG_OPEN | base::File::FLAG_READ)
       .IsValid();
 }
 
 }  // namespace
 
 base::FilePath GetModulePath(base::StringPiece16 module_name,
                              base::string16* version) {
   DCHECK(version);
 
-  base::FilePath module_dir = GetExecutableDir();
+  base::FilePath module_dir;
+  if (!base::PathService::Get(base::DIR_EXE, &module_dir)) {

[Peter Kasting, 2015/11/16 21:39:00]

Can this ever really fail?  It seems like it should always be possible to get
the executable directory.  Certainly the old code didn't check for
GetModuleFileNameW() failing.

[fdoray, 2015/11/16 22:01:36]

It should never fail.

+    LOG(ERROR) << "Cannot get current executable directory.";

[Peter Kasting, 2015/11/16 21:39:00]

We normally avoid logging statements unless you have a specific plan to gather
their data and act on it.  In this case I don't think you gain anything from
logging here.

(I would remove the logging statement below while you're at it.)

[fdoray, 2015/11/16 22:01:36]

Done.

+    return base::FilePath();
+  }
+
   base::FilePath module = module_dir.Append(module_name);
   if (ModuleCanBeRead(module))
     return module;
 
   base::string16 version_string(GetCurrentModuleVersion());
   if (version_string.empty()) {
     LOG(ERROR) << "No valid Chrome version found";
     return base::FilePath();
   }
   *version = version_string;
   return module_dir.Append(version_string).Append(module_name);
 }
 
 }  // namespace installer