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

components/feature_engagement/public/feature_list.h

Index: components/feature_engagement/public/feature_list.h
diff --git a/components/feature_engagement/public/feature_list.h b/components/feature_engagement/public/feature_list.h
index 207131eb56758007553f624e9c90343f0f10a191..b260327ff2210d3db4650ad72b07180c3058caea 100644
--- a/components/feature_engagement/public/feature_list.h
+++ b/components/feature_engagement/public/feature_list.h
@@ -52,6 +52,7 @@ DEFINE_VARIATION_PARAM(kIPHDownloadPageFeature, "IPH_DownloadPage");
 DEFINE_VARIATION_PARAM(kIPHDownloadPageScreenshotFeature,
                        "IPH_DownloadPageScreenshot");
 DEFINE_VARIATION_PARAM(kIPHChromeHomeExpandFeature, "IPH_ChromeHomeExpand");
+DEFINE_VARIATION_PARAM(kIPHMediaDownloadFeature, "IPH_MediaDownload");
 #endif  // defined(OS_ANDROID)
 #if defined(OS_WIN) || defined(OS_LINUX)
 DEFINE_VARIATION_PARAM(kIPHIncognitoWindowFeature, "IPH_IncognitoWindow");
@@ -77,6 +78,7 @@ constexpr flags_ui::FeatureEntry::FeatureVariation
         VARIATION_ENTRY(kIPHDownloadPageFeature),
         VARIATION_ENTRY(kIPHDownloadPageScreenshotFeature),
         VARIATION_ENTRY(kIPHChromeHomeExpandFeature),
+        VARIATION_ENTRY(kIPHMediaDownloadFeature),
 #elif defined(OS_WIN) || defined(OS_LINUX)
         VARIATION_ENTRY(kIPHIncognitoWindowFeature),
         VARIATION_ENTRY(kIPHNewTabFeature),