Fixit: Remove bunch of coverity warnings from chrome/installer/*.

chrome/installer/setup/install.cc

 // Copyright (c) 2009 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 <shlobj.h>
 #include <time.h>
 
 #include "chrome/installer/setup/install.h"
 
 #include "base/command_line.h"
@@ skipping 15 matching lines @@
 #include "chrome/installer/util/work_item.h"
 #include "chrome/installer/util/version.h"
 #include "chrome/installer/util/work_item_list.h"
 
 // Build-time generated include file.
 #include "installer_util_strings.h"
 #include "registered_dlls.h"
 
 namespace {
 
-std::wstring AppendPath(const std::wstring parent_path,
-                        const std::wstring path) {
+std::wstring AppendPath(const std::wstring& parent_path,
+                        const std::wstring& path) {
   std::wstring new_path(parent_path);
   file_util::AppendToPath(&new_path, path);
   return new_path;
 }
 
 void AddChromeToMediaPlayerList() {
   std::wstring reg_path(installer::kMediaPlayerRegPath);
   // registry paths can also be appended like file system path
   file_util::AppendToPath(&reg_path, installer_util::kChromeExe);
   LOG(INFO) << "Adding Chrome to Media player list at " << reg_path;
@@ skipping 224 matching lines @@
   HMODULE module = GetModuleHandle(L"kernel32.dll");
   WOW_FUNC p = reinterpret_cast<WOW_FUNC>(GetProcAddress(module,
                                                          "IsWow64Process"));
   if ((p != NULL) && (!(p)(handle, &is64) || (is64 != FALSE))) {
     return true;
   }
 
   return false;
 }
 
-void RegisterChromeOnMachine(std::wstring install_path, int options) {
+void RegisterChromeOnMachine(const std::wstring& install_path, int options) {
   bool system_level = (options & installer_util::SYSTEM_LEVEL) != 0;
   // Try to add Chrome to Media Player shim inclusion list. We don't do any
   // error checking here because this operation will fail if user doesn't
   // have admin rights and we want to ignore the error.
   AddChromeToMediaPlayerList();
 
   // We try to register Chrome as a valid browser on local machine. This
   // will work only if current user has admin rights.
   std::wstring chrome_exe(install_path);
   file_util::AppendToPath(&chrome_exe, installer_util::kChromeExe);
@@ skipping 253 matching lines @@
 }
 
 std::wstring installer::GetInstallerPathUnderChrome(
     const std::wstring& install_path, const std::wstring& new_version) {
   std::wstring installer_path(install_path);
   file_util::AppendToPath(&installer_path, new_version);
   file_util::AppendToPath(&installer_path, installer_util::kInstallerDir);
   return installer_path;
 }