Fix purify freeze. Revert "Use a priority queue to assure that subresources are resolved asap"

chrome/browser/net/dns_host_info.cc

 // Copyright (c) 2006-2008 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.
 
 // See header file for description of class
 
 #include "chrome/browser/net/dns_host_info.h"
 
 #include <math.h>
 
@@ skipping 59 matching lines @@
 const TimeDelta DnsHostInfo::kMaxNonNetworkDnsLookupDuration(
     TimeDelta::FromMilliseconds(15));
 
 // Used by test ONLY.  The value is otherwise constant.
 void DnsHostInfo::set_cache_expiration(TimeDelta time) {
   kCacheExpirationDuration = time;
 }
 
 void DnsHostInfo::SetQueuedState(ResolutionMotivation motivation) {
   DCHECK(PENDING == state_ || FOUND == state_ || NO_SUCH_NAME == state_);
-  old_prequeue_state_ = state_;
   state_ = QUEUED;
   queue_duration_ = resolve_duration_ = kNullDuration;
   SetMotivation(motivation);
   GetDuration();  // Set time_
   DLogResultsStats("DNS Prefetch in queue");
 }
 
 void DnsHostInfo::SetAssignedState() {
   DCHECK(QUEUED == state_);
   state_ = ASSIGNED;
   queue_duration_ = GetDuration();
   DLogResultsStats("DNS Prefetch assigned");
   UMA_HISTOGRAM_TIMES("DNS.PrefetchQueue", queue_duration_);
 }
 
-void DnsHostInfo::RemoveFromQueue() {
-  DCHECK(ASSIGNED == state_);
-  state_ = old_prequeue_state_;
-  DLogResultsStats("DNS Prefetch reset to prequeue");
-  static const TimeDelta kBoundary = TimeDelta::FromSeconds(2);
-  if (queue_duration_ > kBoundary) {
-    UMA_HISTOGRAM_MEDIUM_TIMES("DNS.QueueRecycledDeltaOver2",
-                               queue_duration_ - kBoundary);
-    return;
-  }
-  // Make a custom linear histogram for the region from 0 to boundary.
-  const size_t kBucketCount = 52;
-  static LinearHistogram histogram("DNS.QueueRecycledUnder2", TimeDelta(),
-                                   kBoundary, kBucketCount);
-  histogram.SetFlags(kUmaTargetedHistogramFlag);
-  histogram.AddTime(queue_duration_);
-}
-
 void DnsHostInfo::SetPendingDeleteState() {
   DCHECK(ASSIGNED == state_  || ASSIGNED_BUT_MARKED == state_);
   state_ = ASSIGNED_BUT_MARKED;
 }
 
 void DnsHostInfo::SetFoundState() {
   DCHECK(ASSIGNED == state_);
   state_ = FOUND;
   resolve_duration_ = GetDuration();
   if (kMaxNonNetworkDnsLookupDuration <= resolve_duration_) {
@@ skipping 31 matching lines @@
 void DnsHostInfo::SetFinishedState(bool was_resolved) {
   DCHECK(STARTED == state_);
   state_ = was_resolved ? FINISHED : FINISHED_UNRESOLVED;
   resolve_duration_ = GetDuration();
   // TODO(jar): Sequence number should be incremented in prefetched HostInfo.
   DLogResultsStats("DNS HTTP Finished");
 }
 
 void DnsHostInfo::SetHostname(const std::string& hostname) {
   if (hostname != hostname_) {
-    DCHECK_EQ(hostname_.size(), 0u);  // Not yet initialized.
+    DCHECK(hostname_.size() == 0);  // Not yet initialized.
     hostname_ = hostname;
   }
 }
 
 // IsStillCached() guesses if the DNS cache still has IP data,
 // or at least remembers results about "not finding host."
 bool DnsHostInfo::IsStillCached() const {
   DCHECK(FOUND == state_ || NO_SUCH_NAME == state_);
 
   // Default MS OS does not cache failures. Hence we could return false almost
   // all the time for that case.  However, we'd never try again to prefetch
   // the value if we returned false that way.  Hence we'll just let the lookup
   // time out the same way as FOUND case.
 
   if (sequence_counter - sequence_number_ > kMaxGuaranteedCacheSize)
     return false;
 
   TimeDelta time_since_resolution = TimeTicks::Now() - time_;
 
   return time_since_resolution < kCacheExpirationDuration;
 }
 
 // Compare the actual navigation DNS latency found in navigation_info, to the
 // previously prefetched info.
 DnsBenefit DnsHostInfo::AccruePrefetchBenefits(DnsHostInfo* navigation_info) {
   DCHECK(FINISHED == navigation_info->state_ ||
          FINISHED_UNRESOLVED == navigation_info->state_);
-  DCHECK_EQ(navigation_info->hostname_, hostname_.data());
+  DCHECK(0 == navigation_info->hostname_.compare(hostname_.data()));
 
   if ((0 == benefits_remaining_.InMilliseconds()) ||
       (FOUND != state_ && NO_SUCH_NAME != state_)) {
     if (FINISHED == navigation_info->state_)
       UMA_HISTOGRAM_LONG_TIMES("DNS.IndependentNavigation",
                                navigation_info->resolve_duration_);
     else
       UMA_HISTOGRAM_LONG_TIMES("DNS.IndependentFailedNavigation",
                                navigation_info->resolve_duration_);
     return PREFETCH_NO_BENEFIT;
@@ skipping 216 matching lines @@
 
     case LEARNED_REFERAL_MOTIVATED:
       return RemoveJs(referring_hostname_);
 
     default:
       return "";
   }
 }
 
 }  // namespace chrome_browser_net