Make Blacklist::IsBlacklist asynchronous (it will need to be for safe

chrome/common/extensions/extension_set.h

Index: chrome/common/extensions/extension_set.h
diff --git a/chrome/common/extensions/extension_set.h b/chrome/common/extensions/extension_set.h
index 072feffe694db796dbe36da8df6bc3d3aa89c9f0..2cc553e3d634767af9a4d06c666cce2f6b1d8566 100644
--- a/chrome/common/extensions/extension_set.h
+++ b/chrome/common/extensions/extension_set.h
@@ -90,7 +90,8 @@ class ExtensionSet {
   bool InsertAll(const ExtensionSet& extensions);
 
   // Removes the specified extension.
-  void Remove(const std::string& id);
+  // Returns true if the set contained the specified extnesion.
+  bool Remove(const std::string& id);
 
   // Removes all extensions.
   void Clear();
@@ -123,6 +124,9 @@ class ExtensionSet {
   // Look up an Extension object by id.
   const extensions::Extension* GetByID(const std::string& id) const;
 
+  // Gets the IDs of all extensions in the set.
+  std::set<std::string> GetIDs() const;
+
   // Returns true if |info| should get extension api bindings and be permitted
   // to make api calls. Note that this is independent of what extension
   // permissions the given extension has been granted.