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);
diff --git a/core/java/android/text/TextLine.java b/core/java/android/text/TextLine.java
index 479242c..605b91d 100644
--- a/core/java/android/text/TextLine.java
+++ b/core/java/android/text/TextLine.java
@@ -739,16 +739,14 @@
 
         float ret = 0;
 
-        int contextLen = contextEnd - contextStart;
         if (needWidth || (c != null && (wp.bgColor != 0 || wp.underlineColor != 0 || runIsRtl))) {
             if (mCharsValid) {
-                ret = wp.getTextRunAdvances(mChars, start, runLen,
-                        contextStart, contextLen, runIsRtl, null, 0);
+                ret = wp.getRunAdvance(mChars, start, contextEnd, contextStart, contextEnd,
+                        runIsRtl, end);
             } else {
                 int delta = mStart;
-                ret = wp.getTextRunAdvances(mText, delta + start,
-                        delta + end, delta + contextStart, delta + contextEnd,
-                        runIsRtl, null, 0);
+                ret = wp.getRunAdvance(mText, delta + start, delta + contextEnd,
+                        delta + contextStart, delta + contextEnd, runIsRtl, delta + end);
             }
         }