compositor-worker: plumb element id and mutable properties

third_party/WebKit/public/platform/WebLayer.h

Index: third_party/WebKit/public/platform/WebLayer.h
diff --git a/third_party/WebKit/public/platform/WebLayer.h b/third_party/WebKit/public/platform/WebLayer.h
index 83089ca7248ee0fa599542965cbdc6f3bb3a497e..fa3e3ae47b4c2ce8ad168f2f7b908973802f298a 100644
--- a/third_party/WebKit/public/platform/WebLayer.h
+++ b/third_party/WebKit/public/platform/WebLayer.h
@@ -235,6 +235,12 @@ public:
     virtual bool isOrphan() const = 0;
 
     virtual void setWebLayerClient(WebLayerClient*) = 0;
+
+    virtual void setElementId(uint64_t) = 0;
+    virtual uint64_t elementId() const = 0;
+
+    virtual void setMutableProperties(uint32_t) = 0;
+    virtual uint32_t mutableProperties() const = 0;
 };
 
 } // namespace blink