Pass MotionEvent tilt angles to Blink on Android.

content/browser/renderer_host/input/motion_event_android.cc

Index: content/browser/renderer_host/input/motion_event_android.cc
diff --git a/content/browser/renderer_host/input/motion_event_android.cc b/content/browser/renderer_host/input/motion_event_android.cc
index 8d36c812cc0084dc9ba3d5cb2d9fa0459ff23832..4045a1875fd9e200d55c37457c14947e9ca33f7e 100644
--- a/content/browser/renderer_host/input/motion_event_android.cc
+++ b/content/browser/renderer_host/input/motion_event_android.cc
@@ -125,6 +125,7 @@ MotionEventAndroid::Pointer::Pointer(jint id,
                                      jfloat touch_major_pixels,
                                      jfloat touch_minor_pixels,
                                      jfloat orientation_rad,
+                                     jfloat tilt_rad,
                                      jint tool_type)
     : id(id),
       pos_x_pixels(pos_x_pixels),
@@ -132,6 +133,7 @@ MotionEventAndroid::Pointer::Pointer(jint id,
       touch_major_pixels(touch_major_pixels),
       touch_minor_pixels(touch_minor_pixels),
       orientation_rad(orientation_rad),
+      tilt_rad(tilt_rad),
       tool_type(tool_type) {
 }
 
@@ -140,6 +142,7 @@ MotionEventAndroid::CachedPointer::CachedPointer()
       touch_major(0),
       touch_minor(0),
       orientation(0),
+      tilt(0),
       tool_type(TOOL_TYPE_UNKNOWN) {
 }
 
@@ -269,6 +272,56 @@ float MotionEventAndroid::GetPressure(size_t pointer_index) const {
       AttachCurrentThread(), event_.obj(), pointer_index);
 }
 
+float MotionEventAndroid::GetTilt(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, cached_pointer_count_);
+  if (pointer_index < MAX_POINTERS_TO_CACHE)
+    return cached_pointers_[pointer_index].tilt;
+  if (!event_.obj())
+    return 0.f;
+  return ToValidFloat(Java_MotionEvent_getAxisValueF_I_I(
+      AttachCurrentThread(), event_.obj(), AXIS_TILT, pointer_index));
+}
+
+// TODO(e_hakkinen): Remove either this or GetTiltX and GetTiltY.
+float MotionEventAndroid::GetTiltOrientation(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, cached_pointer_count_);
+  if (GetToolType(pointer_index) != MotionEvent::TOOL_TYPE_STYLUS)
+    return 0.f;
+  float orientation;
+  if (pointer_index < MAX_POINTERS_TO_CACHE)
+    orientation = cached_pointers_[pointer_index].orientation;
+  else if (!event_.obj())
+    return 0.f;
+  else
+    orientation = ToValidFloat(Java_MotionEvent_getOrientationF_I(
+        AttachCurrentThread(), event_.obj(), pointer_index));
+  return orientation < 0 ? orientation + M_PI : orientation - M_PI;
+}
+
+// TODO(e_hakkinen): Remove either this and GetTiltY or GetTiltOrientation.
+float MotionEventAndroid::GetTiltX(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, cached_pointer_count_);
+  if (GetToolType(pointer_index) != MotionEvent::TOOL_TYPE_STYLUS)
+    return 0.f;
+  float orientation = GetOrientation(pointer_index);
+  float tilt = GetTilt(pointer_index);
+  // A stylus points to a direction specified by orientation and tilts to
+  // the opposite direction. Coordinate system is left-handed.
+  return atan2(sin(-orientation) * sin(tilt), cos(tilt));
+}
+
+// TODO(e_hakkinen): Remove either this and GetTiltX or GetTiltOrientation.
+float MotionEventAndroid::GetTiltY(size_t pointer_index) const {
+  DCHECK_LT(pointer_index, cached_pointer_count_);
+  if (GetToolType(pointer_index) != MotionEvent::TOOL_TYPE_STYLUS)
+    return 0.f;
+  float orientation = GetOrientation(pointer_index);
+  float tilt = GetTilt(pointer_index);
+  // A stylus points to a direction specified by orientation and tilts to
+  // the opposite direction. Coordinate system is left-handed.
+  return atan2(cos(-orientation) * sin(tilt), cos(tilt));
+}
+
 base::TimeTicks MotionEventAndroid::GetEventTime() const {
   return cached_time_;
 }
@@ -332,6 +385,7 @@ MotionEventAndroid::CachedPointer MotionEventAndroid::FromAndroidPointer(
   result.touch_major = ToDips(pointer.touch_major_pixels);
   result.touch_minor = ToDips(pointer.touch_minor_pixels);
   result.orientation = ToValidFloat(pointer.orientation_rad);
+  result.tilt = ToValidFloat(pointer.tilt_rad);
   result.tool_type = FromAndroidToolType(pointer.tool_type);
   return result;
 }