bluetooth: Populate Web Bluetooth blacklist from variations:: parameter.

content/public/browser/content_browser_client.cc

Index: content/public/browser/content_browser_client.cc
diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
index b74452ac81549d87ec8c2e09f43730ecd51a27d6..5adb55529f851c638d3dab0d661779bbdd135170 100644
--- a/content/public/browser/content_browser_client.cc
+++ b/content/public/browser/content_browser_client.cc
@@ -225,6 +225,10 @@ ContentBrowserClient::AllowWebBluetooth(
   return AllowWebBluetoothResult::ALLOW;
 }
 
+std::string ContentBrowserClient::GetWebBluetoothBlacklist() {
+  return "";
+}
+
 QuotaPermissionContext* ContentBrowserClient::CreateQuotaPermissionContext() {
   return nullptr;
 }