Add support to update_engine_client for -app_version and -omaha_url.

omaha_request_params.h

 // Copyright (c) 2010 The Chromium OS 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 49 matching lines @@
 
   // Suggested defaults
   static const char* const kAppId;
   static const char* const kOsPlatform;
   static const char* const kOsVersion;
   static const char* const kUpdateUrl;
 };
 
 class OmahaRequestDeviceParams : public OmahaRequestParams {
  public:
-  explicit OmahaRequestDeviceParams() {}
+  OmahaRequestDeviceParams() {}
 
-  // Initializes all the data in the object. Returns true on success,
-  // false otherwise.
-  bool Init();
+  // Initializes all the data in the object. Non-empty
+  // |in_app_version| or |in_update_url| prevents automatic detection
+  // of the parameter. Returns true on success, false otherwise.
+  bool Init(const std::string& in_app_version,
+            const std::string& in_update_url);
 
   // For unit-tests.
   void set_root(const std::string& root) { root_ = root; }
 
  private:
   // Gets a machine-local ID (for now, first MAC address we find).
   bool GetMachineId(std::string* out_id) const;
 
   // Fetches the value for a given key from
   // /mnt/stateful_partition/etc/lsb-release if possible. Failing that,
   // it looks for the key in /etc/lsb-release.
   std::string GetLsbValue(const std::string& key,
                           const std::string& default_value) const;
 
   // Gets the machine type (e.g. "i686").
   std::string GetMachineType() const;
 
   // When reading files, prepend root_ to the paths. Useful for testing.
   std::string root_;
 
   DISALLOW_COPY_AND_ASSIGN(OmahaRequestDeviceParams);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_OMAHA_REQUEST_PARAMS_H__