Move Android user agent generation to native code

base/sys_info.h

Index: base/sys_info.h
diff --git a/base/sys_info.h b/base/sys_info.h
index c95415e40872786a6ab022c59ff906ab237841c6..af9f017fce00099589b67a3c74580fe9b4e751d0 100644
--- a/base/sys_info.h
+++ b/base/sys_info.h
@@ -81,6 +81,15 @@ class BASE_EXPORT SysInfo {
 #endif // defined(OS_CHROMEOS)
 
 #if defined(OS_ANDROID)
+  // Returns the Android build's codename.
+  static std::string GetAndroidBuildCodename();
+
+  // Returns the Android build ID.
+  static std::string GetAndroidBuildID();
+
+  // Returns the device's name.
+  static std::string GetDeviceName();
+
   static int DalvikHeapSizeMB();
 #endif // defined(OS_ANDROID)
 };