1 files changed, 57 insertions, 0 deletions
diff --git a/layout/base/DisplayItemScrollClip.cpp b/layout/base/DisplayItemScrollClip.cpp
new file mode 100644
index 000000000..a78a43dbd
--- /dev/null
+++ b/layout/base/DisplayItemScrollClip.cpp
@@ -0,0 +1,57 @@
+/* -*- Mode: C++; tab-width: 20; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "DisplayItemScrollClip.h"
+
+#include "DisplayItemClip.h"
+
+namespace mozilla {
+
+/* static */ bool
+DisplayItemScrollClip::IsAncestor(const DisplayItemScrollClip* aAncestor,
+                                  const DisplayItemScrollClip* aDescendant)
+{
+  if (!aAncestor) {
+    // null means root.
+    return true;
+  }
+
+  for (const DisplayItemScrollClip* sc = aDescendant; sc; sc = sc->mParent) {
+    if (sc == aAncestor) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+bool
+DisplayItemScrollClip::HasRoundedCorners() const
+{
+  for (const DisplayItemScrollClip* scrollClip = this;
+       scrollClip; scrollClip = scrollClip->mParent) {
+    if (scrollClip->mClip->GetRoundedRectCount() > 0) {
+      return true;
+    }
+  }
+  return false;
+}
+
+/* static */ nsCString
+DisplayItemScrollClip::ToString(const DisplayItemScrollClip* aScrollClip)
+{
+  nsAutoCString str;
+  for (const DisplayItemScrollClip* scrollClip = aScrollClip;
+       scrollClip; scrollClip = scrollClip->mParent) {
+    str.AppendPrintf("<%s>%s", scrollClip->mClip ? scrollClip->mClip->ToString().get() : "null",
+                     scrollClip->mIsAsyncScrollable ? " [async-scrollable]" : "");
+    if (scrollClip->mParent) {
+      str.Append(", ");
+    }
+  }
+  return str;
+}
+
+} // namespace mozilla