Make update over cellular an option for user

chromeos/dbus/update_engine_client.h

Index: chromeos/dbus/update_engine_client.h
diff --git a/chromeos/dbus/update_engine_client.h b/chromeos/dbus/update_engine_client.h
index 94c89ea7b50546c2f449b43f537636602f90d047..5206aa6e722b8553742d6dee27324f650de77430 100644
--- a/chromeos/dbus/update_engine_client.h
+++ b/chromeos/dbus/update_engine_client.h
@@ -40,7 +40,8 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
     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,
   };
 
   // The status of the ongoing update attempt.
@@ -84,7 +85,7 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
 
   // Called once RequestUpdateCheck() is complete. Takes one parameter:
   // - UpdateCheckResult: the result of the update check.
-  typedef base::Callback<void(UpdateCheckResult)> UpdateCheckCallback;
+  using UpdateCheckCallback = base::Callback<void(UpdateCheckResult)>;
 
   // Requests an update check and calls |callback| when completed.
   virtual void RequestUpdateCheck(const UpdateCheckCallback& callback) = 0;
@@ -97,7 +98,7 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
 
   // Called once CanRollbackCheck() is complete. Takes one parameter:
   // - bool: the result of the rollback availability check.
-  typedef base::Callback<void(bool can_rollback)> RollbackCheckCallback;
+  using RollbackCheckCallback = base::Callback<void(bool can_rollback)>;
 
   // Checks if Rollback is available and calls |callback| when completed.
   virtual void CanRollbackCheck(
@@ -105,8 +106,8 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
 
   // Called once GetChannel() is complete. Takes one parameter;
   // - string: the channel name like "beta-channel".
-  typedef base::Callback<void(const std::string& channel_name)>
-      GetChannelCallback;
+  using GetChannelCallback =
+      base::Callback<void(const std::string& channel_name)>;
 
   // Returns the last status the object received from the update engine.
   //
@@ -137,8 +138,8 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
 
   // Called once GetEolStatus() is complete. Takes one parameter;
   // - EndOfLife Status: the end of life status of the device.
-  typedef base::Callback<void(update_engine::EndOfLifeStatus status)>
-      GetEolStatusCallback;
+  using GetEolStatusCallback =
+      base::Callback<void(update_engine::EndOfLifeStatus status)>;
 
   // Get EndOfLife status of the device and calls |callback| when completed.
   virtual void GetEolStatus(const GetEolStatusCallback& callback) = 0;
@@ -149,6 +150,27 @@ class CHROMEOS_EXPORT UpdateEngineClient : public DBusClient {
       bool allowed,
       const base::Closure& callback) = 0;
 
+  // Called once SetUpdateOverCellularTarget() is complete. Takes one parameter;
+  // - success: indicates whether the target is set successfully.
+  using SetUpdateOverCellularTargetCallback =
+      base::Callback<void(bool success)>;
+
+  // Sets the target in the preferences maintained by update engine which then
+  // performs update to this given target after RequestUpdateCheck() is invoked
+  // in the |callback|.
+  // - target_version: the Chrome OS version we want to update to.
+  // - target_size: the size of that Chrome OS version in bytes.
+  // These two parameters are a failsafe to prevent downloading an update user
+  // didn't agree to. They should be set using the version and size we received
+  // from update engine when it broadcasts NEED_PERMISSION_TO_UPDATE. They are
+  // used by update engine to double-check with update server in case there's a
+  // new update available or a delta update becomes a full update with larger
+  // size.
+  virtual void SetUpdateOverCellularTarget(
+      const std::string& target_version,
+      int64_t target_size,
+      const SetUpdateOverCellularTargetCallback& callback) = 0;
+
   // Returns an empty UpdateCheckCallback that does nothing.
   static UpdateCheckCallback EmptyUpdateCheckCallback();