Make update over cellular an option for user

chromeos/dbus/update_engine_client.h

 // Copyright (c) 2012 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 CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
 #define CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 22 matching lines @@
   enum UpdateStatusOperation {
     UPDATE_STATUS_ERROR = -1,
     UPDATE_STATUS_IDLE = 0,
     UPDATE_STATUS_CHECKING_FOR_UPDATE,
     UPDATE_STATUS_UPDATE_AVAILABLE,
     UPDATE_STATUS_DOWNLOADING,
     UPDATE_STATUS_VERIFYING,
     UPDATE_STATUS_FINALIZING,
     UPDATE_STATUS_UPDATED_NEED_REBOOT,
     UPDATE_STATUS_REPORTING_ERROR_EVENT,
-    UPDATE_STATUS_ATTEMPTING_ROLLBACK
+    UPDATE_STATUS_ATTEMPTING_ROLLBACK,
+    UPDATE_STATUS_NEED_PERMISSION_TO_UPDATE

[Daniel Erat, 2017/05/12 13:37:03]

nit: put trailing comma after last item in lists

[weidongg, 2017/05/12 16:33:17]

Done.

   };
 
   // The status of the ongoing update attempt.
   struct Status {
     Status() : status(UPDATE_STATUS_IDLE),
                download_progress(0.0),
                last_checked_time(0),
                new_size(0) {
     }
 
@@ skipping 88 matching lines @@
 
   // Get EndOfLife status of the device and calls |callback| when completed.
   virtual void GetEolStatus(const GetEolStatusCallback& callback) = 0;
 
   // Either allow or disallow receiving updates over cellular connections.
   // Synchronous (blocking) method.
   virtual void SetUpdateOverCellularPermission(
       bool allowed,
       const base::Closure& callback) = 0;
 
+  // Called once SetUpdateOverCellularTarget() is complete. Takes one parameter;
+  // - success: indicates whether the target is set successfully.
+  typedef base::Callback<void(bool)> SetTargetCallback;

[Daniel Erat, 2017/05/12 13:37:03]

i think that 'using' is preferred now.

this should probably also be SetUpdateOverCellularTargetCallback.

[weidongg, 2017/05/12 16:33:17]

Do you mean I should 'using base::Callback;' at the beginning of the file?

[Daniel Erat, 2017/05/12 16:44:48]

no, this:

  using SetUpdateOverCellularTargetCallback =
      base::Callback<void(bool success)>;

(i think you can include parameter names in callbacks)

[weidongg, 2017/05/12 17:00:15]

Done.

+
+  // Set the target in the preferences maintained by update engine which then
+  // performs update to this given target after |RequestUpdateCheck| is invoked

[Daniel Erat, 2017/05/12 13:37:03]

i think we usually just use || around variable names. functions are usually
written as RequestUpdateCheck() (including in the comment you added above).

[weidongg, 2017/05/12 16:33:16]

Done.

+  // in the |callback|.
+  virtual void SetUpdateOverCellularTarget(
+      const std::string& target_version,
+      int64_t target_size,

[Daniel Erat, 2017/05/12 13:37:03]

please document what target_version and target_size contain. is target_version a
chrome os version number? mind giving an example?

[weidongg, 2017/05/12 16:33:17]

Ok, I add explanation.

+      const SetTargetCallback& callback) = 0;
+
   // Returns an empty UpdateCheckCallback that does nothing.
   static UpdateCheckCallback EmptyUpdateCheckCallback();
 
   // Creates the instance.
   static UpdateEngineClient* Create(DBusClientImplementationType type);
 
   // Returns true if |target_channel| is more stable than |current_channel|.
   static bool IsTargetChannelMoreStable(const std::string& current_channel,
                                         const std::string& target_channel);
 
  protected:
   // Create() should be used instead.
   UpdateEngineClient();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(UpdateEngineClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_UPDATE_ENGINE_CLIENT_H_