Create --disable-extensions-except switch

chrome/common/chrome_switches.cc

Index: chrome/common/chrome_switches.cc
diff --git a/chrome/common/chrome_switches.cc b/chrome/common/chrome_switches.cc
index a125d337c7edd38610435a2ba76f5d90e21ad662..45c039f8e27dd89491b519e08605b45e54247259 100644
--- a/chrome/common/chrome_switches.cc
+++ b/chrome/common/chrome_switches.cc
@@ -238,6 +238,9 @@ const char kDisableDownloadNotification[] = "disable-download-notification";
 // Disable extensions.
 const char kDisableExtensions[]             = "disable-extensions";
 
+// Disable extensions except those specified in a comma-separated list.
+const char kDisableExtensionsExcept[] = "disable-extensions-except";
+
 // Disable checking for user opt-in for extensions that want to inject script
 // into file URLs (ie, always allow it). This is used during automated testing.
 const char kDisableExtensionsFileAccessCheck[] =
@@ -1300,6 +1303,13 @@ bool AboutInSettingsEnabled() {
              ::switches::kDisableAboutInSettings);
 }
 
+bool ExtensionsDisabled() {
+  return base::CommandLine::ForCurrentProcess()->HasSwitch(
+             ::switches::kDisableExtensions) ||
+         base::CommandLine::ForCurrentProcess()->HasSwitch(
+             ::switches::kDisableExtensionsExcept);
+}
+
 bool MdExtensionsEnabled() {
   return base::CommandLine::ForCurrentProcess()->HasSwitch(
       ::switches::kEnableMaterialDesignExtensions);