Mark HiddenValue API as deprecated

BUG=none
R=vogelheim@chromium.org

Review URL: https://codereview.chromium.org/1459373003

Cr-Commit-Position: refs/heads/master@{#32340}

include/v8.h

@@ -2919,12 +2919,12 @@ class V8_EXPORT Object : public Value {
    */
   int GetIdentityHash();
 
-  V8_DEPRECATE_SOON("Use v8::Object::SetPrivate instead.",
-                    bool SetHiddenValue(Local<String> key, Local<Value> value));
-  V8_DEPRECATE_SOON("Use v8::Object::GetPrivate instead.",
-                    Local<Value> GetHiddenValue(Local<String> key));
-  V8_DEPRECATE_SOON("Use v8::Object::DeletePrivate instead.",
-                    bool DeleteHiddenValue(Local<String> key));
+  V8_DEPRECATED("Use v8::Object::SetPrivate instead.",
+                bool SetHiddenValue(Local<String> key, Local<Value> value));
+  V8_DEPRECATED("Use v8::Object::GetPrivate instead.",
+                Local<Value> GetHiddenValue(Local<String> key));
+  V8_DEPRECATED("Use v8::Object::DeletePrivate instead.",
+                bool DeleteHiddenValue(Local<String> key));
 
   /**
    * Clone this object with a fast but shallow copy.  Values will point