Remove unused Extension::InstallType

extensions/common/extension.h

 // Copyright (c) 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 EXTENSIONS_COMMON_EXTENSION_H_
 #define EXTENSIONS_COMMON_EXTENSION_H_
 
 #include <algorithm>
 #include <iosfwd>
 #include <map>
@@ skipping 83 matching lines @@
     DISABLE_UNKNOWN_FROM_SYNC = 1 << 5,
     // DISABLE_PERMISSIONS_CONSENT = 1 << 6,  // Deprecated.
     // DISABLE_KNOWN_DISABLED = 1 << 7,  // Deprecated.
     DISABLE_NOT_VERIFIED = 1 << 8,  // Disabled because we could not verify
                                     // the install.
     DISABLE_GREYLIST = 1 << 9,
     DISABLE_CORRUPTED = 1 << 10,
     DISABLE_REMOTE_INSTALL = 1 << 11
   };
 
-  enum InstallType {
-    INSTALL_ERROR,
-    DOWNGRADE,
-    REINSTALL,
-    UPGRADE,
-    NEW_INSTALL
-  };
-
   // A base class for parsed manifest data that APIs want to store on
   // the extension. Related to base::SupportsUserData, but with an immutable
   // thread-safe interface to match Extension.
   struct ManifestData {
     virtual ~ManifestData() {}
   };
 
   // Do not change the order of entries or remove entries in this list
   // as this is used in UMA_HISTOGRAM_ENUMERATIONs about extensions.
   enum InitFromValueFlags {
@@ skipping 447 matching lines @@
 
   UpdatedExtensionPermissionsInfo(
       const Extension* extension,
       const PermissionSet* permissions,
       Reason reason);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_COMMON_EXTENSION_H_