Implement touch exploration touch typing

ui/chromeos/touch_exploration_controller.h

Index: ui/chromeos/touch_exploration_controller.h
diff --git a/ui/chromeos/touch_exploration_controller.h b/ui/chromeos/touch_exploration_controller.h
index 6727c2a5eded9d6faf66f69cc16bfa2c649ddee5..ffd3476ae52cc3089f33a8a3d02deb76e5472051 100644
--- a/ui/chromeos/touch_exploration_controller.h
+++ b/ui/chromeos/touch_exploration_controller.h
@@ -194,6 +194,10 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
   // |bounds| are in root window coordinates.
   void SetExcludeBounds(const gfx::Rect& bounds);
 
+  // For touch explore release state that fall within |bounds|, causes a tap to

[Daniel Erat, 2017/05/30 17:15:50]

nit: s/state/states/

[David Tseng, 2017/05/30 17:48:50]

Done.

+  // be synthesized and dispatched to the anchor point.

[Daniel Erat, 2017/05/30 17:15:50]

this comment seems a bit misleading, since this method just saves the bounds and
doesn't actually dispatch the tap, right?

would something like this be more accurate?

// Updates |lift_activation_bounds_| so that _____ (insert method
// name here) can later synthesize and dispatch a tap to the anchor
// point if the touch exploration release state falls within |bounds|.

[David Tseng, 2017/05/30 17:48:50]

Done.

+  void SetLiftActivationBounds(const gfx::Rect& bounds);
+
  private:
   friend class TouchExplorationControllerTestApi;
 
@@ -296,7 +300,9 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
 
   void PlaySoundForTimer();
 
-  void SendSimulatedClick();
+  void SendSimulatedClickOrTap();

[Daniel Erat, 2017/05/30 17:15:50]

please add comments above these methods documenting what they do. in particular,
please document how this method decides between clicks and taps, and how
MaybeSend... determines whether it should send the tap or not.

[David Tseng, 2017/05/30 17:48:50]

Done.

+  void SendSimulatedTap();
+  void MaybeSendSimulatedTapInLiftActivationBounds(const ui::TouchEvent& event);
 
   // Some constants used in touch_exploration_controller:
 
@@ -514,6 +520,8 @@ class UI_CHROMEOS_EXPORT TouchExplorationController
   // rewritten when TouchExplorationController is running.
   TouchAccessibilityEnabler* touch_accessibility_enabler_;
 
+  gfx::Rect lift_activation_bounds_;

[Daniel Erat, 2017/05/30 17:15:50]

add a comment documenting what this contains

[David Tseng, 2017/05/30 17:48:50]

Done.

+
   DISALLOW_COPY_AND_ASSIGN(TouchExplorationController);
 };