compositor-worker: plumb element id and mutable properties

third_party/WebKit/Source/core/dom/Element.h

Index: third_party/WebKit/Source/core/dom/Element.h
diff --git a/third_party/WebKit/Source/core/dom/Element.h b/third_party/WebKit/Source/core/dom/Element.h
index 5a54f02f8c593c6a5ba010bac182c45e0f6444e6..55f3688d63f4fa3e4a221a40212eaa387ba417d0 100644
--- a/third_party/WebKit/Source/core/dom/Element.h
+++ b/third_party/WebKit/Source/core/dom/Element.h
@@ -530,8 +530,15 @@ public:
     void setTabIndex(int);
     short tabIndex() const override;
 
-    void incrementProxyCount();
-    void decrementProxyCount();
+    // A compositor proxy is a very limited wrapper around an element. It
+    // exposes only those properties that are requested at the time the proxy is
+    // created. In order to know which properties are actually proxied, we
+    // maintain a count of the number of compositor proxies associated with each
+    // property.
+    bool hasCompositorProxy() const;
+    void incrementCompositorProxiedProperties(uint32_t mutableProperties);
+    void decrementCompositorProxiedProperties(uint32_t mutableProperties);
+    uint32_t compositorMutableProperties() const;
 
     // Helpers for V8DOMActivityLogger::logEvent.  They call logEvent only if
     // the element is inDocument() and the context is an isolated world.