X11: Better timestamp handling for _NET_ACTIVE_WINDOW

chrome/browser/process_singleton_posix.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.
 
 // On Linux, when the user tries to launch a second copy of chrome, we check
 // for a socket in the user's profile directory.  If the socket file is open we
 // send a message to the first chrome browser process with the current
 // directory and second process command line flags.  The second process then
 // exits.
 //
@@ skipping 63 matching lines @@
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/threading/platform_thread.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "build/build_config.h"
 #include "chrome/common/chrome_constants.h"
+#include "chrome/common/chrome_switches.h"
 #include "chrome/grit/chromium_strings.h"
 #include "chrome/grit/generated_resources.h"
 #include "content/public/browser/browser_thread.h"
 #include "net/base/network_interfaces.h"
 #include "ui/base/l10n/l10n_util.h"
 
 #if defined(OS_LINUX)
 #include "chrome/browser/ui/process_singleton_dialog_linux.h"
 #endif
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+#include "ui/events/platform/x11/x11_event_source.h"
+#endif
+
 #if defined(TOOLKIT_VIEWS) && defined(OS_LINUX) && !defined(OS_CHROMEOS)
 #include "ui/views/linux_ui/linux_ui.h"
 #endif
 
 using content::BrowserThread;
 
 namespace {
 
 // Timeout for the current browser process to respond. 20 seconds should be
 // enough.
@@ skipping 706 matching lines @@
     if (retries == retry_attempts) {
       // Retries failed.  Kill the unresponsive chrome process and continue.
       if (!kill_unresponsive || !KillProcessByLockPath())
         return PROFILE_IN_USE;
       return PROCESS_NONE;
     }
 
     base::PlatformThread::Sleep(sleep_interval);
   }
 
+#if defined(OS_LINUX) && !defined(OS_CHROMEOS)
+  base::CommandLine::ForCurrentProcess()->AppendSwitchASCII(
+      switches::kWmUserTimeMs,
+      base::Uint64ToString(
+          ui::X11EventSource::GetInstance()->UpdateServerTime()));
+#endif
+

[Tom (Use chromium acct), 2016/05/06 20:42:00]

This doesn't seem like the best place to put this.  However, it's the only place
where we know another process exists, and before we actually send the arguments.

Maybe this could be moved to ChromeBrowserMainParts::PreCreateThreadsImpl?  We
would need to call UpdateServerTime anyway when we make the first call to
Activate() since wm_user_time_ms is initialized to 0.  However, then the new
--wm-user-time-ms flag will redundantly set the server time again (although that
shouldn't matter now that we have the new logic in set_wm_user_time_ms)

[Elliot Glaysher, 2016/05/06 21:13:13]

I agree that this is really not a good place for this, and putting this in
something like ChromeBrowserMainExtraPartsX11 would be a better place for this
to live.

[Tom (Use chromium acct), 2016/05/06 22:09:43]

Done.

   timeval socket_timeout = TimeDeltaToTimeVal(timeout);
   setsockopt(socket.fd(),
              SOL_SOCKET,
              SO_SNDTIMEO,
              &socket_timeout,
              sizeof(socket_timeout));
 
   // Found another process, prepare our command line
   // format is "START\0<current dir>\0<argv[0]>\0...\0<argv[n]>".
   std::string to_send(kStartToken);
@@ skipping 225 matching lines @@
 }
 
 void ProcessSingleton::KillProcess(int pid) {
   // TODO(james.su@gmail.com): Is SIGKILL ok?
   int rv = kill(static_cast<base::ProcessHandle>(pid), SIGKILL);
   // ESRCH = No Such Process (can happen if the other process is already in
   // progress of shutting down and finishes before we try to kill it).
   DCHECK(rv == 0 || errno == ESRCH) << "Error killing process: "
                                     << base::safe_strerror(errno);
 }