Try to fix the possible bug in base::Time:Now() that can cause the crashing later in icu code calle…

base/time_posix.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 "base/time.h"
 
 #include <sys/time.h>
 #include <time.h>
 #include <unistd.h>
 
@@ skipping 52 matching lines @@
 // to convert from time_t (Unix epoch) and internal (Windows epoch).
 // static
 const int64 Time::kTimeTToMicrosecondsOffset = kWindowsEpochDeltaMicroseconds;
 
 // static
 Time Time::Now() {
   struct timeval tv;
   struct timezone tz = { 0, 0 };  // UTC
   if (gettimeofday(&tv, &tz) != 0) {
     DCHECK(0) << "Could not determine time of day";
+    LOG_ERRNO(ERROR) << "Call to gettimeofday failed.";
+    // Return null instead of uninitialized |tv| value, which contains random
+    // garbage data. This may result in the crash seen in crbug.com/147570.
+    return Time();
   }
   // Combine seconds and microseconds in a 64-bit field containing microseconds
   // since the epoch.  That's enough for nearly 600 centuries.  Adjust from
   // Unix (1970) to Windows (1601) epoch.
   return Time((tv.tv_sec * kMicrosecondsPerSecond + tv.tv_usec) +
       kWindowsEpochDeltaMicroseconds);
 }
 
 // static
 Time Time::NowFromSystemTime() {
@@ skipping 206 matching lines @@
     result.tv_usec = static_cast<suseconds_t>(Time::kMicrosecondsPerSecond) - 1;
     return result;
   }
   int64 us = us_ - kTimeTToMicrosecondsOffset;
   result.tv_sec = us / Time::kMicrosecondsPerSecond;
   result.tv_usec = us % Time::kMicrosecondsPerSecond;
   return result;
 }
 
 }  // namespace base