Improve Location object.

Add getElapsedRealtimeNano():

Currently Location just has getTime() and setTime() based on UTC time.
This is entirely unreliable since it is not guaranteed monotonic.
There is a lot of code that compares fix age based on deltas -
and it is all broken in the case of a system clock change. System
clock can change when switching cellular networks (and in some
cases when switching towers).

Document the meaning of getAccuracy():
It is the horizontal, 95% confidence radius.

Make some fields mandatory if they are reported by a LocationProvider:

All Locations returned by a LocationProvider must include at the
minimum a lat, long, timestamps, and accuracy. This is necessary
to perform fused location. There are no public API's for applications
to feed locations into a location provider so this should not cause
any breakage.

If a LocationProvider does not fill in enough fields on a Location
object then it is dropped, and logged.

Bug: 4305998
Change-Id: I7df77125d8a64e174d7bc8c2708661b4f33461ea

1 files changed, 2 insertions, 0 deletions

diff --git a/api/current.txt b/api/current.txt
index 8ae12a2..093d4c3 100644
--- a/api/current.txt
+++ b/api/current.txt
@@ -10504,6 +10504,7 @@ package android.location {
     method public float getAccuracy();
     method public double getAltitude();
     method public float getBearing();
+    method public long getElapsedRealtimeNano();
     method public android.os.Bundle getExtras();
     method public double getLatitude();
     method public double getLongitude();
@@ -10523,6 +10524,7 @@ package android.location {
     method public void setAccuracy(float);
     method public void setAltitude(double);
     method public void setBearing(float);
+    method public void setElapsedRealtimeNano(long);
     method public void setExtras(android.os.Bundle);
     method public void setLatitude(double);
     method public void setLongitude(double);