Add workaround to UrlBar scroll crash.

In some instances, the attempted scroll position
is beyond the length of the URL.  This crashes some
versions of Android and hangs others.  This caps the
scroll position to the text length and adds some logging
to attempt to catch this locally.

BUG=859219

Change-Id: I7859d37ede741c5ce81d85df400cbe4bea2ccdeb
Reviewed-on: https://chromium-review.googlesource.com/c/1332209Reviewed-by: Theresa <twellington@chromium.org>
Commit-Queue: Ted Choc <tedchoc@chromium.org>
Cr-Commit-Position: refs/heads/master@{#607672}

chrome/android/java/src/org/chromium/chrome/browser/omnibox/UrlBar.java

@@ -708,7 +708,12 @@ public class UrlBar extends AutocompleteEditText {
 
         Layout textLayout = getLayout();
         assert getLayout().getLineCount() == 1;
-        final int originEndIndex = mOriginEndIndex;
+        final int originEndIndex = Math.min(mOriginEndIndex, url.length());
+        if (mOriginEndIndex > url.length()) {
+            // If discovered locally, please update crbug.com/859219 with the steps to reproduce.
+            assert false : "Attempting to scroll past the end of the URL: " + url + ", end index: "
+                           + mOriginEndIndex;
+        }
         float endPointX = textLayout.getPrimaryHorizontal(originEndIndex);
         // Compare the position offset of the last character and the character prior to determine
         // the LTR-ness of the final component of the URL.