chrome/blink: Add functionality for in-product help for media elements.

components/feature_engagement_tracker/public/feature_constants.cc

Index: components/feature_engagement_tracker/public/feature_constants.cc
diff --git a/components/feature_engagement_tracker/public/feature_constants.cc b/components/feature_engagement_tracker/public/feature_constants.cc
index 6b3448f77dda1f344db988d60f3e9a5fc069024b..a2fe50cf608520eb68e5f343530fd91fafe334e5 100644
--- a/components/feature_engagement_tracker/public/feature_constants.cc
+++ b/components/feature_engagement_tracker/public/feature_constants.cc
@@ -21,6 +21,8 @@ const base::Feature kIPHDownloadPageFeature{"IPH_DownloadPage",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kIPHDownloadHomeFeature{"IPH_DownloadHome",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kIPHMediaDownloadFeature{"IPH_MediaDownload",
+                                             base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // OS_ANDROID
 
 }  // namespace feature_engagement_tracker