Fix null-dereference caused by r532302

We need to check if there is a frame before calling CanExecuteScripts.

Bug: 806681, 806705
Change-Id: I717cbb92478806b8f2687b099c62558f5abc7f03
Reviewed-on: https://chromium-review.googlesource.com/891304Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Commit-Queue: Rob Buis <rob.buis@samsung.com>
Cr-Commit-Position: refs/heads/master@{#532850}

third_party/WebKit/LayoutTests/fast/innerHTML/806705-crash.html

+<script src="../../resources/testharness.js"></script>
+<script src="../../resources/testharnessreport.js"></script>
+<script>
+test(function() {
+var d = document.implementation.createHTMLDocument();
+var e = d.body.innerHTML = '<noscript>noscript</noscript>';
+assert_equals(d.querySelector('noscript').innerHTML, 'noscript');
+});
+</script>

third_party/WebKit/Source/core/editing/serializers/MarkupFormatter.cpp

@@ -479,7 +479,7 @@ EntityMask MarkupFormatter::EntityMaskForText(const Text& text) const {
        *parent_name == xmpTag || *parent_name == iframeTag ||
        *parent_name == plaintextTag || *parent_name == noembedTag ||
        *parent_name == noframesTag ||
-       (*parent_name == noscriptTag &&
+       (*parent_name == noscriptTag && text.GetDocument().GetFrame() &&
         text.GetDocument().CanExecuteScripts(kNotAboutToExecuteScript))))
     return kEntityMaskInCDATA;
   return kEntityMaskInHTMLPCDATA;