Replicating WebFrame::uniqueName across renderers.

third_party/WebKit/Source/core/page/FrameTree.h

Index: third_party/WebKit/Source/core/page/FrameTree.h
diff --git a/third_party/WebKit/Source/core/page/FrameTree.h b/third_party/WebKit/Source/core/page/FrameTree.h
index 37493906a646304b783ede027f16b6efaf73bbdf..9477035954752d56ec70b8bcf38ab76eea3b17ca 100644
--- a/third_party/WebKit/Source/core/page/FrameTree.h
+++ b/third_party/WebKit/Source/core/page/FrameTree.h
@@ -70,9 +70,16 @@ public:
 
     DECLARE_TRACE();
 
+    AtomicString calculateUniqueNameForNewChildFrame(
+        const AtomicString& name,
+        const AtomicString& fallbackName = nullAtom) const;
+
 private:
     Frame* deepLastChild() const;
-    AtomicString uniqueChildName(const AtomicString& requestedName) const;
+    AtomicString calculateUniqueNameForChildFrame(
+        bool existingChildFrame,
+        const AtomicString& requestedName,
+        const AtomicString& fallbackName = nullAtom) const;
     bool uniqueNameExists(const AtomicString& name) const;
 
     RawPtrWillBeMember<Frame> m_thisFrame;