Fix unit tests with TrackPathDescriptor.

In MapOverlay, for testing, expose a getter and a setter
for TrackPathDescriptor instead of newPath and getLastPath.

In SingleColorTrackPathPainter, refactor "new Path" to a
newPath method so that tests can override the newPath method
to provide a mockPath.

MyTracks/src/com/google/android/apps/mytracks/MapOverlay.java

@@ -35,7 +35,6 @@ import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.content.res.Resources;
 import android.graphics.Canvas;
 import android.graphics.Paint;
-import android.graphics.Path;
 import android.graphics.Point;
 import android.graphics.Rect;
 import android.graphics.drawable.Drawable;
@@ -305,17 +304,17 @@ public class MapOverlay extends Overlay implements OnSharedPreferenceChangeListe
     int cy = mapView.getMapCenter().getLatitudeE6();
     return new Rect(cx - w / 2, cy - h / 2, cx + w / 2, cy + h / 2);
   }
-
-  // Visible for testing.
-  Path newPath() {
-    return new Path();
-  }
-
-  // Visible for testing.
-  public Path getLastPath() {
-    return trackPathPainter.getLastPath();
+ 
+  // Visible for testing
+  public TrackPathPainter getTrackPathPainter() {
+    return trackPathPainter;
   }
   
+  // Visible for testing
+  public void setTrackPathPainter(TrackPathPainter trackPathPainter) {
+    this.trackPathPainter = trackPathPainter;
+  }
+
   private void drawWaypoints(Canvas canvas, Projection projection) {
     synchronized (waypoints) {;
       for (Waypoint wpt : waypoints) {

MyTracks/src/com/google/android/apps/mytracks/maps/SingleColorTrackPathPainter.java

@@ -57,7 +57,7 @@ public class SingleColorTrackPathPainter implements TrackPathPainter {
     final Point pt = new Point();
     // Loop over track points.
     int numPoints = points.size();
-    path = new Path();
+    path = newPath();
     path.incReserve(numPoints);
     
     for (int i = startLocationIdx; i < numPoints ; ++i) {
@@ -104,4 +104,9 @@ public class SingleColorTrackPathPainter implements TrackPathPainter {
   public Path getLastPath() {
     return path;
   }
+  
+  // Visible for testing
+  public Path newPath() {
+    return new Path();
+  }
 }