Scale touch event radius

ash/touch/touch_transformer_controller.h

Index: ash/touch/touch_transformer_controller.h
diff --git a/ash/touch/touch_transformer_controller.h b/ash/touch/touch_transformer_controller.h
index f06be2957e1ac43faee9bdc74c15241fb01e4ca4..8512186603d757b0bb8d096596e469130f0f9077 100644
--- a/ash/touch/touch_transformer_controller.h
+++ b/ash/touch/touch_transformer_controller.h
@@ -34,6 +34,8 @@ class ASH_EXPORT TouchTransformerController
                            TouchTransformerMirrorModePillarboxing);
   FRIEND_TEST_ALL_PREFIXES(TouchTransformerControllerTest,
                            TouchTransformerExtendedMode);
+  FRIEND_TEST_ALL_PREFIXES(TouchTransformerControllerTest,
+                           TouchRadiusScale);
 
   bool ShouldComputeMirrorModeTouchTransformer(
       const DisplayInfo& touch_display) const ;
@@ -44,6 +46,8 @@ class ASH_EXPORT TouchTransformerController
   gfx::Transform GetExtendedModeTouchTransformer(
       const DisplayInfo& touch_display, const gfx::Size& fb_size) const;
 
+  double GetTouchResolutionScale(const DisplayInfo& touch_display) const;
+
   // For unittests only.
   bool force_compute_mirror_mode_touch_transformer_;