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 4b945a4a865bcd4721e779589fc857b67a903d88..aae3173cb05f0c43550ca39fe344603b50510f8d 100644
--- a/components/feature_engagement_tracker/public/feature_constants.cc
+++ b/components/feature_engagement_tracker/public/feature_constants.cc
@@ -23,6 +23,8 @@ const base::Feature kIPHDownloadPageFeature{"IPH_DownloadPage",
                                             base::FEATURE_DISABLED_BY_DEFAULT};
 const base::Feature kIPHDownloadPageScreenshotFeature{
     "IPH_DownloadPageScreenshot", base::FEATURE_DISABLED_BY_DEFAULT};
+const base::Feature kIPHMediaDownloadFeature{"IPH_MediaDownload",
+                                             base::FEATURE_DISABLED_BY_DEFAULT};
 #endif  // defined(OS_ANDROID)
 
 #if defined(OS_WIN) || defined(OS_LINUX)