Super-fast getLineWidth for BL

Bug: 24678704
Change-Id: I952964f450d19b1e127753d00833eb7b34473bba

core/java/android/text/BoringLayout.java

@@ -363,6 +363,11 @@ public class BoringLayout extends Layout implements TextUtils.EllipsizeCallback
         return mMax;
     }
 
+    @Override
+    public float getLineWidth(int line) {
+        return (line == 0 ? mMax : 0);
+    }
+
     @Override
     public final Directions getLineDirections(int line) {
         return Layout.DIRS_ALL_LEFT_TO_RIGHT;