Parse /etc/lsb-release only once on ChromeOS

chrome/browser/chromeos/version_loader.h

 // Copyright (c) 2011 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_VERSION_LOADER_H_
 #define CHROME_BROWSER_CHROMEOS_VERSION_LOADER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 35 matching lines @@
   // Asynchronously requests the version.
   // If |full_version| is true version string with extra info is extracted,
   // otherwise it's in short format x.x.xx.x.
   CancelableTaskTracker::TaskId GetVersion(VersionFormat format,
                                            const GetVersionCallback& callback,
                                            CancelableTaskTracker* tracker);
 
   CancelableTaskTracker::TaskId GetFirmware(const GetFirmwareCallback& callback,
                                             CancelableTaskTracker* tracker);
 
-  static const char kFullVersionPrefix[];
-  static const char kVersionPrefix[];
-  static const char kFirmwarePrefix[];
-
  private:
-  FRIEND_TEST_ALL_PREFIXES(VersionLoaderTest, ParseFullVersion);
-  FRIEND_TEST_ALL_PREFIXES(VersionLoaderTest, ParseVersion);
   FRIEND_TEST_ALL_PREFIXES(VersionLoaderTest, ParseFirmware);
 
   // VersionLoader calls into the Backend in the blocking thread pool to load
   // and extract the version.
   class Backend : public base::RefCountedThreadSafe<Backend> {
    public:
     Backend() {}
 
-    // Calls ParseVersion to get the version # and notifies request.
-    // This is invoked in the blocking thread pool.
-    // If |full_version| is true then extra info is passed in version string.
+    // Gets the version number from base::SysInfo. This is invoked on the
+    // blocking thread pool.
     void GetVersion(VersionFormat format, std::string* version);
 
-    // Calls ParseFirmware to get the firmware # and notifies request.
-    // This is invoked in the blocking thread pool.
+    // Calls ParseFirmware to get the firmware value. This is invoked on the
+    // blocking thread pool.
     void GetFirmware(std::string* firmware);
 
    private:
     friend class base::RefCountedThreadSafe<Backend>;
 
     ~Backend() {}
 
     DISALLOW_COPY_AND_ASSIGN(Backend);
   };
 
-  // Extracts the version from the file.
-  // |prefix| specifies what key defines version data.
-  static std::string ParseVersion(const std::string& contents,
-                                  const std::string& prefix);
-
   // Extracts the firmware from the file.
   static std::string ParseFirmware(const std::string& contents);
 
   scoped_refptr<Backend> backend_;
 
   DISALLOW_COPY_AND_ASSIGN(VersionLoader);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_VERSION_LOADER_H_