Record chrome's startup time, to be used in future retention experiments

- For windows in the registry
- not implemented for posix

BUG=32474
TEST=none


Review URL: http://codereview.chromium.org/558009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@37360 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/browser_main.cc

@@ -978,6 +978,8 @@ int BrowserMain(const MainFunctionParams& parameters) {
     // the main message loop.
     if (browser_init.Start(parsed_command_line, std::wstring(), profile,
                            &result_code)) {
+      // Record now as the last succesful chrome start.
+      GoogleUpdateSettings::SetLastRunTime();
       // Call Recycle() here as late as possible, before going into the loop
       // because Start() will add things to it while creating the main window.
       if (pool)

chrome/browser/google_update_settings_posix.cc

@@ -69,3 +69,17 @@ bool GoogleUpdateSettings::SetMetricsId(const std::wstring& client_id) {
   google_update::posix_guid = WideToASCII(client_id);
   return GoogleUpdateSettings::SetCollectStatsConsent(true);
 }
+
+// GetLastRunTime and SetLastRunTime are not implemented for posix. Their
+// currebnt return values signal failure which the caller is designed to
+// handle.
+
+// static
+int GoogleUpdateSettings::GetLastRunTime() {
+  return -1;
+}
+
+// static
+bool GoogleUpdateSettings::SetLastRunTime() {
+  return false;
+}