Convert app_launch_index and page_index from int to StringOrdinal.

chrome/common/extensions/extension_constants.h

 // Copyright (c) 2011 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_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #define CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_
 #pragma once
 
 #include <string>
 
@@ skipping 326 matching lines @@
 
   // The extension id of the bookmark manager.
   extern const char* kBookmarkManagerId;
 
   // The extension id of the Web Store component application.
   extern const char* kWebStoreAppId;
 
   // The extension id of the Cloud Print component application.
   extern const char* kCloudPrintAppId;
 
+  // The string used to specify an unset app_launch_index or
+  // page index value.
+  extern const char* kUnsetIndex;
+
   // Note: this structure is an ASN.1 which encodes the algorithm used
   // with its parameters. This is defined in PKCS #1 v2.1 (RFC 3447).
   // It is encoding: { OID sha1WithRSAEncryption      PARAMETERS NULL }
   const uint8 kSignatureAlgorithm[15] = {
     0x30, 0x0d, 0x06, 0x09, 0x2a, 0x86, 0x48, 0x86,
     0xf7, 0x0d, 0x01, 0x01, 0x05, 0x05, 0x00
   };
 
   // Don't remove items or change the order of this enum.  It's used in
   // histograms and preferences.
@@ skipping 100 matching lines @@
   };
 
   enum UnloadedExtensionReason {
     UNLOAD_REASON_DISABLE,    // Extension is being disabled.
     UNLOAD_REASON_UPDATE,     // Extension is being updated to a newer version.
     UNLOAD_REASON_UNINSTALL,  // Extension is being uninstalled.
   };
 } // extension_misc
 
 #endif  // CHROME_COMMON_EXTENSIONS_EXTENSION_CONSTANTS_H_