Fix preferred logical widths of orthogonal writing modes

third_party/WebKit/Source/core/frame/OrthogonalWritingModeRootList.cpp

Index: third_party/WebKit/Source/core/frame/OrthogonalWritingModeRootList.cpp
diff --git a/third_party/WebKit/Source/core/frame/OrthogonalWritingModeRootList.cpp b/third_party/WebKit/Source/core/frame/OrthogonalWritingModeRootList.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..5f2bd3f95b1ac0e0223b381e31b7b47e45dae9b3
--- /dev/null
+++ b/third_party/WebKit/Source/core/frame/OrthogonalWritingModeRootList.cpp
@@ -0,0 +1,40 @@
+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/frame/OrthogonalWritingModeRootList.h"
+
+#include "core/layout/LayoutObject.h"
+#include <algorithm>
+
+namespace blink {
+
+LayoutObject* OrthogonalWritingModeRootList::takeDeepestRoot()
+{
+    if (!m_isIterating) {
+        if (m_roots.isEmpty())
+            return nullptr;
+
+        if (m_isOrderedListDirty) {
+            copyToVector(m_roots, m_orderedRoots);
+            std::sort(m_orderedRoots.begin(), m_orderedRoots.end());
+            m_isOrderedListDirty = m_isAnyRemoved = false;
+        }
+
+        m_isIterating = true;
+        m_lastTaken = m_orderedRoots.rbegin();
+        return m_lastTaken->object;
+    }
+
+    for (++m_lastTaken; m_lastTaken != m_orderedRoots.rend(); ++m_lastTaken) {
+        LayoutObject* object = m_lastTaken->object;
+        // Check removals while iterating.
+        if (!m_isAnyRemoved || m_roots.contains(object))

[esprehn, 2016/01/31 00:44:56]

what is this? How can the list be mutated while iterating?

This should be impossible, you take the sorted list after layout and iterate it
directly, you should never have mutations.

[kojii, 2016/01/31 01:12:20]

Just mimic'ed what LayoutSubtreeRootList does, I'll remove in the next patch.

+            return object;
+    }
+
+    m_isIterating = false;
+    return nullptr;
+}
+
+} // namespace blink