Make chrome.exe rendezvous with existing chrome process earlier.

chrome/app/chrome_exe_main_win.cc

 // Copyright (c) 2011 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 <windows.h>
 #include <tchar.h>
 
 #include "base/at_exit.h"
 #include "base/command_line.h"
+#include "base/files/file_path.h"
 #include "chrome/app/breakpad_win.h"
 #include "chrome/app/client_util.h"
 #include "chrome/app/metro_driver_win.h"
+#include "chrome/browser/chrome_process_finder_win.h"
+#include "chrome/common/chrome_paths_internal.h"
+#include "chrome/common/chrome_switches.h"
 #include "content/public/app/startup_helper_win.h"
 #include "content/public/common/result_codes.h"
 #include "sandbox/win/src/sandbox_factory.h"
 
 int RunChrome(HINSTANCE instance) {
   bool exit_now = true;
   // We restarted because of a previous crash. Ask user if we should relaunch.
   if (ShowRestartDialogIfCrashed(&exit_now)) {
     if (exit_now)
       return content::RESULT_CODE_NORMAL_EXIT;
   }
 
   // Initialize the sandbox services.
   sandbox::SandboxInterfaceInfo sandbox_info = {0};
   content::InitializeSandboxInfo(&sandbox_info);
 
   // Load and launch the chrome dll. *Everything* happens inside.
   MainDllLoader* loader = MakeMainDllLoader();
   int rc = loader->Launch(instance, &sandbox_info);
   loader->RelaunchChromeBrowserWithNewCommandLineIfNeeded();
   delete loader;
   return rc;
 }
 
+bool AttemptFastNotify() {
+  // We only support the fast path for the default user data dir.
+  if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kUserDataDir))

[pastarmovj, 2013/05/01 10:54:09]

You have to check that the UserDataDir policy is not set either because it can
override the path as well and even has priority over the command line switch. 

[koz (OOO until 15th September), 2013/05/09 01:47:42]

Done.

+    return false;
+
+  base::FilePath udd;

[cpu_(ooo_6.6-7.5), 2013/04/30 19:33:37]

udd -> data_dir

[koz (OOO until 15th September), 2013/05/09 01:47:42]

Done.

+  if (!chrome::GetDefaultUserDataDirectory(&udd))
+    return false;
+  HWND chrome = chrome::FindRunningChromeWindow(udd);
+  if (chrome && chrome::AttemptToNotifyRunningChrome(chrome))
+    return true;
+  return false;
+}
+
 int APIENTRY wWinMain(HINSTANCE instance, HINSTANCE prev, wchar_t*, int) {
   // Initialize the commandline singleton from the environment.
   CommandLine::Init(0, NULL);
   // The exit manager is in charge of calling the dtors of singletons.
   base::AtExitManager exit_manager;
 
+  if (AttemptFastNotify())
+    return 0;
+
   MetroDriver metro_driver;
   if (metro_driver.in_metro_mode())
     return metro_driver.RunInMetro(instance, &RunChrome);
   // Not in metro mode, proceed as normal.
   return RunChrome(instance);
 }