Updates touch calibration API and plumbs through the native touch calibration method

chrome/browser/chromeos/display/touch_calibrator/touch_calibrator_controller.h

 // Copyright 2016 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_DISPLAY_TOUCH_CALIBRATOR_TOUCH_CALIBRATOR_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_DISPLAY_TOUCH_CALIBRATOR_TOUCH_CALIBRATOR_CONTROLLER_H_
 
 #include <map>
 
 #include "ash/display/window_tree_host_manager.h"
@@ skipping 13 matching lines @@
 
 // TouchCalibratorController is responsible for collecting the touch calibration
 // associated data from the user. It instantiates TouchCalibratorView classes to
 // present an interface the user can interact with for calibration.
 // Touch calibration is restricted to calibrate only one display at a time.
 class TouchCalibratorController : public ui::EventHandler,
                                   public ash::WindowTreeHostManager::Observer {
  public:
   using CalibrationPointPairQuad =
       display::TouchCalibrationData::CalibrationPointPairQuad;
+  using TouchCalibrationCallback = base::Callback<void(bool)>;
 
   static const base::TimeDelta kTouchIntervalThreshold;
 
   TouchCalibratorController();
   ~TouchCalibratorController() override;
 
   // ui::EventHandler
   void OnKeyEvent(ui::KeyEvent* event) override;
   void OnTouchEvent(ui::TouchEvent* event) override;
 
   // WindowTreeHostManager::Observer
   void OnDisplayConfigurationChanged() override;
 
   // Starts the calibration process for the given |target_display|.
   void StartCalibration(const display::Display& target_display);
 
+  // Adds a callback that will be called once the calibration has been
+  // completed. This should be called before |StartCalibration()|.
+  void AddCallback(const TouchCalibrationCallback& callback);

[Reilly Grant (use Gerrit), 2017/01/19 02:41:46]

Why not pass this callback to StartCalibration()?

[malaykeshav, 2017/01/19 06:10:38]

I was thinking of making the callback optional in the IDL file, but got lost in
the documentation on to use it. 
Moving the callback to StartCalibration()

+
   // Stops any ongoing calibration process.
   void StopCalibration();
 
   bool is_calibrating() { return is_calibrating_; }
 
  private:
   friend class TouchCalibratorControllerTest;
   FRIEND_TEST_ALL_PREFIXES(TouchCalibratorControllerTest, StartCalibration);
   FRIEND_TEST_ALL_PREFIXES(TouchCalibratorControllerTest, KeyEventIntercept);
   FRIEND_TEST_ALL_PREFIXES(TouchCalibratorControllerTest, TouchThreshold);
@@ skipping 11 matching lines @@
   // was received.
   base::Time last_touch_timestamp_;
 
   // Is true if a touch calibration is already underprocess.
   bool is_calibrating_ = false;
 
   // An array of Calibration point pairs. This stores all the 4 display and
   // touch input point pairs that will be used for calibration.
   CalibrationPointPairQuad touch_point_quad_;
 
+  // A callback to be called when touch calibration completes.
+  TouchCalibrationCallback callback_;
+  bool has_callback_;

[Reilly Grant (use Gerrit), 2017/01/19 02:41:46]

This field is unnecessary. callback_.is_null() will be true if a callback has
not been set.

[malaykeshav, 2017/01/19 06:10:38]

Done

+
   DISALLOW_COPY_AND_ASSIGN(TouchCalibratorController);
 };
 
 }  // namespace chromeos
 #endif  // CHROME_BROWSER_CHROMEOS_DISPLAY_TOUCH_CALIBRATOR_TOUCH_CALIBRATOR_CONTROLLER_H_