Prevent CacheStats from DCHECKing when debugging.

chrome/browser/net/cache_stats.cc

 // Copyright (c) 2012 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/cache_stats.h"
 
 #include "base/metrics/histogram.h"
 #include "base/stl_util.h"
 #include "base/string_number_conversions.h"
 #include "base/timer.h"
@@ skipping 263 matching lines @@
   }
 }
 
 void CacheStats::ScheduleTimer(TabLoadStats* stats) {
   int timer_index = stats->next_timer_index;
   DCHECK(timer_index >= 0 &&
          timer_index < static_cast<int>(arraysize(kStatsCollectionTimesMs)));
   base::TimeDelta delta =
       base::TimeDelta::FromMilliseconds(kStatsCollectionTimesMs[timer_index]);
   delta -= base::TimeTicks::Now() - stats->load_start_time;
+
+  // If the ScheduleTimer call was delayed significantly, like when one's using
+  // a debugger, don't try to start the timer with a negative time.
+  if (delta < base::TimeDelta()) {
+    RemoveTabLoadStats(stats->render_view_id);
+    return;
+  }
+
   stats->timer.Start(FROM_HERE,
                      delta,
                      base::Bind(&CacheStats::TimerCallback,
                                 base::Unretained(this),
                                 base::Unretained(stats)));
 }
 
 void CacheStats::TimerCallback(TabLoadStats* stats) {
   DCHECK(stats->spinner_started);
   base::TimeDelta load_time = base::TimeTicks::Now() - stats->load_start_time;
@@ skipping 39 matching lines @@
   if (type == ChromeURLRequestContext::CONTEXT_TYPE_MAIN)
     main_request_contexts_.insert(context);
 }
 
 void CacheStats::UnregisterURLRequestContext(
     const net::URLRequestContext* context) {
   main_request_contexts_.erase(context);
 }
 
 }  // namespace chrome_browser_net