Adding sampling support to installer crash reporter client.

chrome/install_static/install_util.h

 // Copyright 2016 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.
 // This file contains helper functions which provide information about the
 // current version of Chrome. This includes channel information, version
 // information etc. This functionality is provided by using functions in
 // kernel32 and advapi32. No other dependencies are allowed in this file.
 
 #ifndef CHROME_INSTALL_STATIC_INSTALL_UTIL_H_
 #define CHROME_INSTALL_STATIC_INSTALL_UTIL_H_
@@ skipping 16 matching lines @@
 extern const wchar_t kChromeChannelUnknown[];
 extern const wchar_t kChromeChannelCanary[];
 extern const wchar_t kChromeChannelDev[];
 extern const wchar_t kChromeChannelBeta[];
 extern const wchar_t kChromeChannelStable[];
 extern const wchar_t kChromeChannelStableExplicit[];
 extern const wchar_t kRegPathClientState[];
 extern const wchar_t kRegPathClientStateMedium[];
 extern const wchar_t kRegPathChromePolicy[];
 extern const wchar_t kRegApField[];
+// Registry key to store the stats/crash sampling state of Chrome. If set to 1,
+// stats and crash reports will be uploaded in line with the user's consent,
+// otherwise, uploads will be disabled. It is used to sample clients, to reduce
+// server load for metics and crashes. This is controlled by the
+// MetricsReporting feature in chrome_metrics_services_manager_client.cc and is
+// written when metrics services are started up and when consent changes.
+extern const wchar_t kRegValueChromeStatsSample[];
 // Used to retrieve consent for uploading crashes and metrics.
 extern const wchar_t kRegValueUsageStats[];
 extern const wchar_t kUninstallArgumentsField[];
 extern const wchar_t kMetricsReportingEnabled[];
 extern const wchar_t kAppGuidCanary[];
 extern const wchar_t kAppGuidGoogleChrome[];
 extern const wchar_t kAppGuidGoogleBinaries[];
 
 // TODO(ananta)
 // https://crbug.com/604923
@@ skipping 168 matching lines @@
 // value of the |switch_name| passed in.
 std::string GetSwitchValueFromCommandLine(const std::string& command_line,
                                           const std::string& switch_name);
 
 // Caches the |ProcessType| of the current process.
 extern ProcessType g_process_type;
 
 }  // namespace install_static
 
 #endif  // CHROME_INSTALL_STATIC_INSTALL_UTIL_H_