Implemented a "Last Updated" field for the about page of Chrome OS.

base/sys_info_chromeos.cc

Index: base/sys_info_chromeos.cc
diff --git a/base/sys_info_chromeos.cc b/base/sys_info_chromeos.cc
index f84a2a5f81ba78469895b0275f1bd672f379466e..619fb979e03209d15042a55b254cec946544d54c 100644
--- a/base/sys_info_chromeos.cc
+++ b/base/sys_info_chromeos.cc
@@ -113,4 +113,17 @@ void SysInfo::ParseLsbRelease(const std::string& lsb_release,
   }
 }
 
+// static
+bool SysInfo::GetTimeLastUpdated(base::Time* time) {
+  FilePath path(kLinuxStandardBaseReleaseFile);
+  base::PlatformFileInfo info;
+
+  if (file_util::GetFileInfo(path, &info)) {
+    *time = info.last_modified;
+    return true;
+  }
+
+  return false;
+}
+
 }  // namespace base