linux and chromeos: Turn on -Wunused-const-variable.

chrome/browser/ui/webui/chromeos/imageburner/imageburner_ui.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/ui/webui/chromeos/imageburner/imageburner_ui.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/i18n/rtl.h"
 #include "base/strings/string16.h"
@@ skipping 13 matching lines @@
 #include "url/gurl.h"
 
 namespace chromeos {
 namespace imageburner {
 
 namespace {
 
 const char kPropertyDevicePath[] = "devicePath";
 const char kPropertyFilePath[] = "filePath";
 const char kPropertyLabel[] = "label";
-const char kPropertyPath[] = "path";
 const char kPropertyDeviceType[] = "type";
 
 // Link displayed on imageburner ui.
 const char kMoreInfoLink[] =
     "http://www.chromium.org/chromium-os/chromiumos-design-docs/recovery-mode";
 
 content::WebUIDataSource* CreateImageburnerUIHTMLSource() {
   content::WebUIDataSource* source =
       content::WebUIDataSource::Create(chrome::kChromeUIImageBurnerHost);
 
@@ skipping 277 matching lines @@
 
 ImageBurnUI::ImageBurnUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   chromeos::imageburner::WebUIHandler* handler =
       new chromeos::imageburner::WebUIHandler(web_ui->GetWebContents());
   web_ui->AddMessageHandler(handler);
 
   Profile* profile = Profile::FromWebUI(web_ui);
   content::WebUIDataSource::Add(
       profile, chromeos::imageburner::CreateImageburnerUIHTMLSource());
 }