Remove PRODUCT_STRING_PATH from chrome_constants.h on Windows.

components/browser_watcher/watcher_metrics_provider_win.cc

 // Copyright (c) 2014 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 "components/browser_watcher/watcher_metrics_provider_win.h"
 
 #include <stddef.h>
 
 #include <limits>
 #include <vector>
@@ skipping 173 matching lines @@
   if (res != ERROR_FILE_NOT_FOUND && res != ERROR_SUCCESS)
     DVLOG(1) << "Failed to delete exit code key " << registry_path;
 }
 
 }  // namespace
 
 const char WatcherMetricsProviderWin::kBrowserExitCodeHistogramName[] =
     "Stability.BrowserExitCodes";
 
 WatcherMetricsProviderWin::WatcherMetricsProviderWin(
-    const base::char16* registry_path,
+    const base::string16& registry_path,
     base::TaskRunner* cleanup_io_task_runner)
     : recording_enabled_(false),
       cleanup_scheduled_(false),
       registry_path_(registry_path),
       cleanup_io_task_runner_(cleanup_io_task_runner) {
   DCHECK(cleanup_io_task_runner_);
 }
 
 WatcherMetricsProviderWin::~WatcherMetricsProviderWin() {
 }
@@ skipping 20 matching lines @@
   // user account, there's a small race that will double-report the exit codes
   // from both/multiple instances. This ought to be vanishingly rare and will
   // only manifest as low-level "random" noise. To work around this it would be
   // necessary to implement some form of global locking, which is not worth it
   // here.
   RecordExitCodes(registry_path_);
   DeleteExitFunnels(registry_path_);
 }
 
 }  // namespace browser_watcher