Oilpan: extend tracing over WebFrame trees.

Source/core/loader/FrameLoader.cpp

Index: Source/core/loader/FrameLoader.cpp
diff --git a/Source/core/loader/FrameLoader.cpp b/Source/core/loader/FrameLoader.cpp
index 37d3db67ca3ef6d3766955301d8b4fe4d2314454..25a7c1ca5f57a70a70fdc27f1b7789ad8af22e92 100644
--- a/Source/core/loader/FrameLoader.cpp
+++ b/Source/core/loader/FrameLoader.cpp
@@ -251,8 +251,9 @@ void FrameLoader::didExplicitOpen()
 
 void FrameLoader::clear()
 {
-    // clear() is called during (Local)Frame finalization and when creating
-    // a new Document within it (DocumentLoader::createWriterFor().)
+    // clear() is called during (Local)Frame detachment or when
+    // reusing a FrameLoader by putting a new Document within it
+    // (DocumentLoader::ensureWriter().)
     if (m_stateMachine.creatingInitialEmptyDocument())
         return;