html_viewer: Correctly set axis and orientation of MotionEvent.

MotionEvent's orientation is in radian, and it falls within [-π/2, π/2). However,
TouchEvent's rotation-angle is in degrees, and it falls within [0, 180). So make
sure the conversion from rotation-angle to orientation happens correctly. Add
PointerProperties::SetAxisAndOrientation() as a convenience function to do this
correctly.

This fixes a crash in mandoline when touching the screen in landspace mode.

BUG=none

Review URL: https://codereview.chromium.org/1202283005

Cr-Commit-Position: refs/heads/master@{#336187}

1 files changed, 6 insertions, 0 deletions

diff --git a/ui/events/gesture_detection/motion_event_generic.h b/ui/events/gesture_detection/motion_event_generic.h
index 6357342..2a9a606 100644
--- a/ui/events/gesture_detection/motion_event_generic.h
+++ b/ui/events/gesture_detection/motion_event_generic.h
@@ -18,6 +18,12 @@ struct GESTURE_DETECTION_EXPORT PointerProperties {
   PointerProperties(float x, float y, float touch_major);
   PointerProperties(const MotionEvent& event, size_t pointer_index);
 
+  // Sets |touch_major|, |touch_minor|, and |orientation| from the given radius
+  // and rotation angle (in degrees).
+  void SetAxesAndOrientation(float radius_x,
+                             float radius_y,
+                             float rotation_angle_degree);
+
   int id;
   MotionEvent::ToolType tool_type;
   float x;