Fix "unreachable code" warnings (MSVC warning 4702) in chrome/browser/.

chrome/browser/ui/app_list/app_list_service.cc

 // Copyright 2013 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/ui/app_list/app_list_service.h"
 
 #include "base/command_line.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/process/process_info.h"
@@ skipping 16 matching lines @@
         command_line.GetSwitchValueASCII(switches::kOriginalProcessStartTime);
     int64 remote_start_time;
     base::StringToInt64(start_time_string, &remote_start_time);
     return base::Time::FromInternalValue(remote_start_time);
   }
 
 // base::CurrentProcessInfo::CreationTime() is only defined on some
 // platforms.
 #if defined(OS_WIN) || defined(OS_MACOSX) || defined(OS_LINUX)
   return base::CurrentProcessInfo::CreationTime();
+#else
+  return base::Time();
 #endif
-  return base::Time();
 }
 
 StartupType GetStartupType(const CommandLine& command_line) {
   // The presence of kOriginalProcessStartTime implies that another process
   // has sent us its command line to handle, ie: we are already running.
   if (command_line.HasSwitch(switches::kOriginalProcessStartTime)) {
     return command_line.HasSwitch(switches::kFastStart) ?
         WARM_START_FAST : WARM_START;
   }
   return COLD_START;
@@ skipping 73 matching lines @@
       break;
     case WARM_START_FAST:
       UMA_HISTOGRAM_LONG_TIMES("Startup.ShowAppListWarmStartFast", elapsed);
       break;
   }
 
   RecordStartupInfo(startup, start_time);
   Get(chrome::HOST_DESKTOP_TYPE_NATIVE)->SetAppListNextPaintCallback(
       RecordFirstPaintTiming);
 }