NetLog: Use TimeTicks::UnixEpoch() to calculate timeTickOffset.

net/log/net_log_util.cc

 // Copyright 2014 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 "net/log/net_log_util.h"
 
 #include <algorithm>
 #include <string>
 #include <vector>
 
@@ skipping 254 matching lines @@
     base::DictionaryValue* dict = new base::DictionaryValue();
 
     dict->SetInteger("ADDRESS_FAMILY_UNSPECIFIED", ADDRESS_FAMILY_UNSPECIFIED);
     dict->SetInteger("ADDRESS_FAMILY_IPV4", ADDRESS_FAMILY_IPV4);
     dict->SetInteger("ADDRESS_FAMILY_IPV6", ADDRESS_FAMILY_IPV6);
 
     constants_dict->Set("addressFamily", dict);
   }
 
   // Information about how the "time ticks" values we have given it relate to
-  // actual system times. (We used time ticks throughout since they are stable
-  // across system clock changes).
+  // actual system times.  Time ticks are used throughout since they are stable
+  // across system clock changes.
   {
-    int64 cur_time_ms = (base::Time::Now() - base::Time()).InMilliseconds();
-
-    int64 cur_time_ticks_ms =
-        (base::TimeTicks::Now() - base::TimeTicks()).InMilliseconds();
-
-    // If we add this number to a time tick value, it gives the timestamp.
-    int64 tick_to_time_ms = cur_time_ms - cur_time_ticks_ms;
-
-    // Chrome on all platforms stores times using the Windows epoch
-    // (Jan 1 1601), but the javascript wants a unix epoch.
-    // TODO(eroman): Getting the timestamp relative to the unix epoch should
-    //               be part of the time library.
-    const int64 kUnixEpochMs = 11644473600000LL;
-    int64 tick_to_unix_time_ms = tick_to_time_ms - kUnixEpochMs;
+    int64 tick_to_unix_time_ms =
+        (base::TimeTicks() - base::TimeTicks::UnixEpoch()).InMilliseconds();
 
     // Pass it as a string, since it may be too large to fit in an integer.
     constants_dict->SetString("timeTickOffset",
                               base::Int64ToString(tick_to_unix_time_ms));
   }
 
   // "clientInfo" key is required for some NetLogLogger log readers.
   // Provide a default empty value for compatibility.
   constants_dict->Set("clientInfo", new base::DictionaryValue());
 
@@ skipping 223 matching lines @@
     // fine, since GetRequestStateAsValue() ignores the capture mode.
     NetLog::EntryData entry_data(
         NetLog::TYPE_REQUEST_ALIVE, request->net_log().source(),
         NetLog::PHASE_BEGIN, request->creation_time(), &callback);
     NetLog::Entry entry(&entry_data, NetLogCaptureMode::Default());
     observer->OnAddEntry(entry);
   }
 }
 
 }  // namespace net