Rename "tree of trees" to "composed tree".

third_party/WebKit/Source/core/events/EventPath.cpp

Index: third_party/WebKit/Source/core/events/EventPath.cpp
diff --git a/third_party/WebKit/Source/core/events/EventPath.cpp b/third_party/WebKit/Source/core/events/EventPath.cpp
index d15ebb262473cb4441d0af1e2d1a1016dcb30faf..66442994c7dd9301a7fc65abd87c6efaa568ca4a 100644
--- a/third_party/WebKit/Source/core/events/EventPath.cpp
+++ b/third_party/WebKit/Source/core/events/EventPath.cpp
@@ -157,7 +157,7 @@ void EventPath::calculatePath()
 void EventPath::calculateTreeOrderAndSetNearestAncestorClosedTree()
 {
     // Precondition:
-    //   - TreeScopes in m_treeScopeEventContexts must be *connected* in the same tree of trees.
+    //   - TreeScopes in m_treeScopeEventContexts must be *connected* in the same composed tree.
     //   - The root tree must be included.
     WillBeHeapHashMap<RawPtrWillBeMember<const TreeScope>, RawPtrWillBeMember<TreeScopeEventContext>> treeScopeEventContextMap;
     for (const auto& treeScopeEventContext : m_treeScopeEventContexts)