Add deprecation message for -webkit-background-composite

third_party/WebKit/Source/core/page/Page.h

Index: third_party/WebKit/Source/core/page/Page.h
diff --git a/third_party/WebKit/Source/core/page/Page.h b/third_party/WebKit/Source/core/page/Page.h
index 9b02be16ae6e7d28e1f9e033ac93489841d70713..c9201549e4b8ec0514ccc16e29f0c537e518fa61 100644
--- a/third_party/WebKit/Source/core/page/Page.h
+++ b/third_party/WebKit/Source/core/page/Page.h
@@ -23,6 +23,7 @@
 
 #include "core/CoreExport.h"
 #include "core/dom/ViewportDescription.h"
+#include "core/frame/Deprecation.h"
 #include "core/frame/LocalFrame.h"
 #include "core/frame/OriginsUsingFeatures.h"
 #include "core/frame/SettingsDelegate.h"
@@ -163,6 +164,7 @@ public:
     Settings& settings() const { return *m_settings; }
 
     UseCounter& useCounter() { return m_useCounter; }
+    Deprecation& deprecation() { return m_deprecation; }
     OriginsUsingFeatures& originsUsingFeatures() { return m_originsUsingFeatures; }
 
     void setTabKeyCyclesThroughElements(bool b) { m_tabKeyCyclesThroughElements = b; }
@@ -268,6 +270,7 @@ private:
     OwnPtrWillBeMember<ValidationMessageClient> m_validationMessageClient;
 
     UseCounter m_useCounter;
+    Deprecation m_deprecation;
     OriginsUsingFeatures m_originsUsingFeatures;
 
     bool m_openedByDOM;