MD Settings: Add feature flag for showing content settings in a per-origin view.

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 ecd94eb12115fda54af99cc8511dca23f5bd0dab..7cd2d31c48529d133fbdc28cee691ee9e226806e 100644
--- a/chrome/common/chrome_features.cc
+++ b/chrome/common/chrome_features.cc
@@ -300,6 +300,11 @@ const base::Feature kSafeSearchUrlReporting{"SafeSearchUrlReporting",
 const base::Feature kSimplifiedFullscreenUI{"ViewsSimplifiedFullscreenUI",
                                             base::FEATURE_ENABLED_BY_DEFAULT};
 
+// Enables or disables UI in MD Settings to view content settings grouped by
+// origin.
+const base::Feature kSiteDetails{"SiteDetails",
+                                 base::FEATURE_DISABLED_BY_DEFAULT};
+
 #if defined(SYZYASAN)
 // Enable the deferred free mechanism in the syzyasan module, which helps the
 // performance by deferring some work on the critical path to a background