Fix a DCHECK that could fire in PassiveLogCollector for a particular stream o...

chrome/browser/net/passive_log_collector.cc

 // Copyright (c) 2010 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.
 
 #include "chrome/browser/net/passive_log_collector.h"
 
 #include <algorithm>
 
 #include "base/compiler_specific.h"
 #include "base/string_util.h"
@@ skipping 271 matching lines @@
 
   // After the deletion queue has reached its maximum size, start
   // deleting sources in FIFO order.
   if (deletion_queue_.size() > max_graveyard_size_) {
     uint32 oldest = deletion_queue_.front();
     deletion_queue_.pop_front();
     DeleteSourceInfo(oldest);
   }
 }
 
+void PassiveLogCollector::SourceTracker::EraseFromDeletionQueue(
+    uint32 source_id) {
+  DeletionQueue::iterator it =
+      std::remove(deletion_queue_.begin(), deletion_queue_.end(),
+                  source_id);
+  DCHECK(it != deletion_queue_.end());
+  deletion_queue_.erase(it);
+}
+
 void PassiveLogCollector::SourceTracker::AdjustReferenceCountForSource(
     int offset, uint32 source_id) {
   DCHECK(offset == -1 || offset == 1) << "invalid offset: " << offset;
 
   // In general it is invalid to call AdjustReferenceCountForSource() on
   // source that doesn't exist. However, it is possible that if
   // SourceTracker::Clear() was previously called this can happen.
   SourceIDToInfoMap::iterator it = sources_.find(source_id);
   if (it == sources_.end()) {
     LOG(WARNING) << "Released a reference to nonexistent source.";
     return;
   }
 
   SourceInfo& info = it->second;
   DCHECK_GE(info.reference_count, 0);
   info.reference_count += offset;
 
-  if (info.reference_count < 0) {
+  bool released_unmatched_reference = info.reference_count < 0;
+  if (released_unmatched_reference) {
     // In general this shouldn't happen, however it is possible to reach this
     // state if SourceTracker::Clear() was called earlier.
     LOG(WARNING) << "Released unmatched reference count.";
     info.reference_count = 0;
   }
 
   if (!info.is_alive) {
     if (info.reference_count == 1 && offset == 1) {
       // If we just added a reference to a dead source that had no references,
       // it must have been in the deletion queue, so remove it from the queue.
-      DeletionQueue::iterator it =
-          std::remove(deletion_queue_.begin(), deletion_queue_.end(),
-                      source_id);
-      DCHECK(it != deletion_queue_.end());
-      deletion_queue_.erase(it);
+      EraseFromDeletionQueue(source_id);
     } else if (info.reference_count == 0) {
+      if (released_unmatched_reference)
+        EraseFromDeletionQueue(source_id);
       // If we just released the final reference to a dead source, go ahead
       // and delete it right away.
       DeleteSourceInfo(source_id);
     }
   }
 }
 
 void PassiveLogCollector::SourceTracker::AddReferenceToSourceDependency(
     const net::NetLog::Source& source, SourceInfo* info) {
   // Find the tracker which should be holding |source|.
@@ skipping 218 matching lines @@
 PassiveLogCollector::DNSJobTracker::DoAddEntry(const Entry& entry,
                                                SourceInfo* out_info) {
   AddEntryToSourceInfo(entry, out_info);
   if (entry.type == net::NetLog::TYPE_HOST_RESOLVER_IMPL_JOB &&
       entry.phase == net::NetLog::PHASE_END) {
     return ACTION_MOVE_TO_GRAVEYARD;
   } else {
     return ACTION_NONE;
   }
 }