Create --disable-extensions-except switch

chrome/browser/extensions/extension_service.h

Index: chrome/browser/extensions/extension_service.h
diff --git a/chrome/browser/extensions/extension_service.h b/chrome/browser/extensions/extension_service.h
index 556cc4f388d1cf775eb14147623418b4c4d5afd5..55095502c7d0acb24b9618fcbf93110593881e6b 100644
--- a/chrome/browser/extensions/extension_service.h
+++ b/chrome/browser/extensions/extension_service.h
@@ -456,6 +456,14 @@ class ExtensionService
     external_updates_finished_callback_ = callback;
   }
 
+  void AddExtensionToWhitelist(const std::string& extensionId) {
+    whitelist_.insert(extensionId);
+  }
+
+  bool IsExtensionWhitelisted(const std::string& extensionId) {
+    return whitelist_.find(extensionId) != whitelist_.end();
+  }
+
  private:
   // Reloads the specified extension, sending the onLaunched() event to it if it
   // currently has any window showing. |be_noisy| determines whether noisy
@@ -616,6 +624,9 @@ class ExtensionService
   // These extensions should appear in registry_.
   extensions::ExtensionSet greylist_;
 
+  // Set of whitelisted extensions.
+  std::set<std::string> whitelist_;

[Devlin, 2016/07/25 19:10:29]

Whitelisted for what?

[catmullings, 2016/07/27 01:29:45]

WDYT of enabled_extensions_whitelist_ ?

I could be more specific, but then the variable becomes too long:

whitelist_of_extensions_overriding_disable_extensions_flag

[Devlin, 2016/07/27 17:00:59]

enabled_extensions_whitelist still sounds a little vague to me.  I agree that we
can't be entirely explicit, but maybe something like
"disable_exempted_extensions_"?  Could even be
disable_flag_exempted_extensions_.

[catmullings, 2016/08/04 22:59:30]

Done.

[catmullings, 2016/08/04 22:59:30]

I like  disable_flag_exempted_extensions_. I'll go with that.

+
   // The list of extension installs delayed for various reasons.  The reason
   // for delayed install is stored in ExtensionPrefs. These are not part of
   // ExtensionRegistry because they are not yet installed.