[Blink>Media] Add Chrome feature for disabling autoplay unmuted in WebAPK

chrome/common/chrome_features.cc

Index: chrome/common/chrome_features.cc
diff --git a/chrome/common/chrome_features.cc b/chrome/common/chrome_features.cc
index 174c574f12c8a20a73e949ad9664fa367241bf2d..eb721478de6f992bc62167021f111c2f643683a9 100644
--- a/chrome/common/chrome_features.cc
+++ b/chrome/common/chrome_features.cc
@@ -11,6 +11,12 @@ namespace features {
 
 // All features in alphabetical order.
 
+#if defined(OS_ANDROID)
+const base::Feature kAllowAutoplayUnmutedInWebappManifestScope{
+    "AllowAutoplayUnmutedInWebappManifestScope",
+    base::FEATURE_ENABLED_BY_DEFAULT};
+#endif  // defined(OS_ANDROID)
+
 #if defined(OS_MACOSX)
 // Enables Javascript execution via AppleScript.
 const base::Feature kAppleScriptExecuteJavaScript{