Make TextIterator constructor to take only proper range

third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp

Index: third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp
diff --git a/third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp b/third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp
index 2368499c400e69dd5e1be50b64b2d69bc7656057..28e9ffe76f23ff2fe7e28ffe87a9972c74081b0c 100644
--- a/third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp
+++ b/third_party/WebKit/Source/core/editing/iterators/TextIterator.cpp
@@ -170,13 +170,9 @@ TextIteratorAlgorithm<Strategy>::TextIteratorAlgorithm(
   DCHECK(!start.GetDocument()->View() ||
          !start.GetDocument()->View()->NeedsLayout());
   DCHECK(!start.GetDocument()->NeedsLayoutTreeUpdate());
-
-  if (start.CompareTo(end) > 0) {
-    Initialize(end.ComputeContainerNode(), end.ComputeOffsetInContainerNode(),
-               start.ComputeContainerNode(),
-               start.ComputeOffsetInContainerNode());
-    return;
-  }
+  // To avoid renderer hang, we use |CHECK_LE()| to catch the bad callers
+  // in release build.
+  CHECK_LE(start, end);
   Initialize(start.ComputeContainerNode(), start.ComputeOffsetInContainerNode(),
              end.ComputeContainerNode(), end.ComputeOffsetInContainerNode());
 }