Add base::ExecutableExistsInPath

chrome/browser/printing/printer_manager_dialog_linux.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/printing/printer_manager_dialog.h"
 
 #include <memory>
 
 #include "base/bind.h"
 #include "base/environment.h"
@@ skipping 12 matching lines @@
 
 // KDE printer config command ("system-config-printer-kde") causes the
 // OptionWidget to crash (https://bugs.kde.org/show_bug.cgi?id=271957).
 // Therefore, use GNOME printer config command for KDE.
 const char* const kSystemConfigPrinterCommand[] = {"system-config-printer",
                                                    nullptr};
 
 const char* const kGnomeControlCenterPrintersCommand[] = {
     "gnome-control-center", "printers", nullptr};
 
-bool CommandExists(const char* command) {
-  std::unique_ptr<base::Environment> env(base::Environment::Create());
-  std::string path;
-  if (!env->GetVar("PATH", &path)) {
-    LOG(ERROR) << "No $PATH variable. Assuming no " << command << ".";
-    return false;
-  }
-
-  for (const base::StringPiece& cur_path :
-       base::SplitStringPiece(path, ":", base::KEEP_WHITESPACE,
-                              base::SPLIT_WANT_NONEMPTY)) {
-    base::FilePath file(cur_path);
-    if (base::PathExists(file.Append(command)))
-      return true;
-  }
-  return false;
-}
-
 // Returns true if the dialog was opened successfully.
 bool OpenPrinterConfigDialog(const char* const* command) {
   DCHECK(command);
-  if (!CommandExists(*command))
+  if (!base::ExecutableExistsInPath(base::Environment::Create(), *command))

[mattm, 2016/06/23 21:32:53]

This will leak the Environment. (We should really update Create() to return a
unique_ptr instead of a bare pointer.)

[Lei Zhang, 2016/06/23 21:35:32]

Ditto in chrome/browser/ui/webui/settings_utils_linux.cc. I can make the fix
separately. There's already a bug to do this for base/ APIs.

[Tom (Use chromium acct), 2016/06/23 21:55:12]

I'm going to leave the unique_ptr change to Lei :)

[Tom (Use chromium acct), 2016/06/23 21:55:12]

Done.

     return false;
   std::vector<std::string> argv;
   while (*command)
     argv.push_back(*command++);
   base::Process process = base::LaunchProcess(argv, base::LaunchOptions());
   if (!process.IsValid())
     return false;
   base::EnsureProcessGetsReaped(process.Pid());
   return true;
 }
@@ skipping 28 matching lines @@
 }  // anonymous namespace
 
 namespace printing {
 
 void PrinterManagerDialog::ShowPrinterManagerDialog() {
   BrowserThread::PostTask(BrowserThread::FILE, FROM_HERE,
                           base::Bind(&DetectAndOpenPrinterConfigDialog));
 }
 
 }  // namespace printing