Prevent imbalanced keepalive counts in ProcessManager

extensions/browser/process_manager.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 EXTENSIONS_BROWSER_PROCESS_MANAGER_H_
 #define EXTENSIONS_BROWSER_PROCESS_MANAGER_H_
 
 #include <map>
 #include <set>
 #include <string>
@@ skipping 296 matching lines @@
   // Any interruption obtains a new ID by incrementing
   // last_background_close_sequence_id_ and storing it in background_page_data_
   // for a particular extension. Callbacks and round-trip IPC messages store the
   // value of the extension's close_sequence_id at the beginning of the process.
   // Thus comparisons can be done to halt when IDs no longer match.
   //
   // This counter provides unique IDs even when BackgroundPageData objects are
   // reset.
   uint64 last_background_close_sequence_id_;
 
+  // Tracks pending network requests by opaque ID. This is used to ensure proper
+  // keepalive counting in response to request status updates; e.g., if an
+  // extension URLRequest is constructed and then destroyed without ever
+  // starting, we can receive a completion notification without a corresponding
+  // start notification. In that case we want to avoid decrementing keepalive.
+  std::set<int> pending_network_requests_;
+
   // Must be last member, see doc on WeakPtrFactory.
   base::WeakPtrFactory<ProcessManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ProcessManager);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_PROCESS_MANAGER_H_