Revert "Revert "Use getRunAdvance to position cursor""

This reverts commit 5730c974800a0ffed59a041d9e249a5c42e417db.
diff --git a/core/java/android/text/Layout.java b/core/java/android/text/Layout.java
index f176240..f7027f9 100644
--- a/core/java/android/text/Layout.java
+++ b/core/java/android/text/Layout.java
@@ -1121,6 +1121,7 @@
      * closest to the specified horizontal position.
      */
     public int getOffsetForHorizontal(int line, float horiz) {
+        // TODO: use Paint.getOffsetForAdvance to avoid binary search
         int max = getLineEnd(line) - 1;
         int min = getLineStart(line);
         Directions dirs = getLineDirections(line);