Fix install verification for sideloaded extensions without update urls

chrome/browser/extensions/install_verifier.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_
 #define CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_
 
 #include <queue>
 #include <set>
 #include <string>
@@ skipping 38 matching lines @@
   void Init();
 
   // Do we need to be bootstrapped? (i.e. do we have a signature already). If
   // this is true, then consumers of this class should use Add/AddMany to get
   // an initial one so that MustRemainDisabled can actually check against it.
   bool NeedsBootstrap();
 
   // Returns the timestamp of our InstallSignature, if we have one.
   base::Time SignatureTimestamp();
 
+  // Returns true if |id| is either verified or our stored signature explicitly
+  // tells us that it was invalid when we asked the server about it.
+  bool IsKnownId(const std::string& id);
+
   // A callback for indicating success/failure of adding new ids.
   typedef base::Callback<void(bool)> AddResultCallback;
 
   // Try adding a new |id| (or set of ids) to the list of verified ids. When
   // this process is finished |callback| will be run with success/failure of
   // the signature request (not necessarily whether the ids were verified).
   void Add(const std::string& id, const AddResultCallback& callback);
   void AddMany(const ExtensionIdSet& ids,
                const AddResultCallback& callback);
 
@@ skipping 72 matching lines @@
   // A set of ids that have been provisionally added, which we're willing to
   // consider allowed until we hear back from the server signature request.
   ExtensionIdSet provisional_;
 
   DISALLOW_COPY_AND_ASSIGN(InstallVerifier);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_INSTALL_VERIFIER_H_