TextIteratorAlgorithm should not force layout update in constructor.

third_party/WebKit/Source/web/mac/WebSubstringUtil.mm

Index: third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
diff --git a/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm b/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
index 26f6185fed011efbf3504af0f245d53ba21527b0..6cd6d6625410d4ff9c2755e5960fed33f365b43c 100644
--- a/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
+++ b/third_party/WebKit/Source/web/mac/WebSubstringUtil.mm
@@ -65,6 +65,11 @@ static NSAttributedString* attributedSubstringFromRange(const EphemeralRange& ra
     size_t length = range.endPosition().computeOffsetInContainerNode() - range.startPosition().computeOffsetInContainerNode();
 
     unsigned position = 0;
+
+    // TODO(dglazkov): The use of updateLayoutIgnorePendingStylesheets needs to be audited.
+    // see http://crbug.com/590369 for more details.
+    range.startPosition().document()->updateLayoutIgnorePendingStylesheets();
+
     for (TextIterator it(range.startPosition(), range.endPosition()); !it.atEnd() && [string length] < length; it.advance()) {
         unsigned numCharacters = it.length();
         if (!numCharacters)