compositor-worker: Force elements to grow a layer when a CompositorProxy is created.

Source/core/dom/StyleChangeReason.cpp

Index: Source/core/dom/StyleChangeReason.cpp
diff --git a/Source/core/dom/StyleChangeReason.cpp b/Source/core/dom/StyleChangeReason.cpp
index e3a12e6ad8b335b24368f62624c9df2dfe9081a9..84e0c7c67ed68844bd0042a3ff630ba1b0899fc4 100644
--- a/Source/core/dom/StyleChangeReason.cpp
+++ b/Source/core/dom/StyleChangeReason.cpp
@@ -15,6 +15,7 @@ namespace StyleChangeReason {
 const char ActiveStylesheetsUpdate[] = "ActiveStylesheetsUpdate";
 const char Animation[] = "Animation";
 const char Attribute[] = "Attribute";
+const char CompositorProxy[] = "CompositorProxy";
 const char ControlValue[] = "ControlValue";
 const char Control[] = "Control";
 const char DesignMode[] = "DesignMode";