Workaround for NPE in UrlBar#onTouchEvent()

BUG=757161

Change-Id: Icc9e4a60731cd3f18da1f966fd54ae7733f0366f
Reviewed-on: https://chromium-review.googlesource.com/781103Reviewed-by: Maria Khomenko <mariakhomenko@chromium.org>
Commit-Queue: Changwan Ryu <changwan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#518266}

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

@@ -12,6 +12,7 @@ import android.graphics.Canvas;
 import android.graphics.Paint;
 import android.graphics.Rect;
 import android.net.Uri;
+import android.os.Build;
 import android.os.StrictMode;
 import android.os.SystemClock;
 import android.support.annotation.Nullable;
@@ -408,7 +409,18 @@ public class UrlBar extends AutocompleteEditText {
             if (viewCore != null) viewCore.destroySelectActionMode();
         }
 
-        return super.onTouchEvent(event);
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            return super.onTouchEvent(event);
+        }
+        try {
+            return super.onTouchEvent(event);
+        } catch (NullPointerException e) {
+            // Working around a platform bug (b/25562038) that was fixed in N that can throw an
+            // exception during text selection. We just swallow the exception. The outcome is that
+            // the text selection handle doesn't show.
+            Log.w(TAG, "Ignoring NPE in UrlBar#onTouchEvent.", e);
+            return true;
+        }
     }
 
     @Override