MD Settings: Enable Site Details by default.

Site Details will eventually assume the Page Info bubble's responsibility for
showing all the permissions available to an origin. Get to Site Details by
opening the Page Info bubble on a site and clicking the 'Site settings' button.

This can be flipped via chrome://flags #enable-site-details, or passing the
command line option --enable-features=SiteDetails.

Bug: 656758
Change-Id: Ib81b094a23578ba5efcbcb7272139ee160e6bf79
Reviewed-on: https://chromium-review.googlesource.com/602090
Reviewed-by: Dave Schuyler <dschuyler@chromium.org>
Commit-Queue: Patti <patricialor@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492922}

chrome/common/chrome_features.cc

@@ -371,7 +371,7 @@ const base::Feature kSimplifiedFullscreenUI{"ViewsSimplifiedFullscreenUI",
 // Enables or disables UI in MD Settings to view content settings grouped by
 // origin.
 const base::Feature kSiteDetails{"SiteDetails",
-                                 base::FEATURE_DISABLED_BY_DEFAULT};
+                                 base::FEATURE_ENABLED_BY_DEFAULT};
 
 #if !defined(OS_ANDROID)
 // Enables delaying the navigation of background tabs in order to improve