Remove ProcessSingleton::FoundOtherProcessWindow() as it is no longer required.

chrome/browser/chrome_browser_main.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 "chrome/browser/chrome_browser_main.h"
 
 #if defined(TOOLKIT_GTK)
 #include <gtk/gtk.h>
 #endif
 
@@ skipping 1029 matching lines @@
 #endif
 
   // Desktop construction occurs here, (required before profile creation).
   PreProfileInit();
 
   std::string try_chrome =
       parsed_command_line().GetSwitchValueASCII(switches::kTryChromeAgain);
   if (!try_chrome.empty()) {
 #if defined(OS_WIN)
     // Setup.exe has determined that we need to run a retention experiment
-    // and has lauched chrome to show the experiment UI.
-    if (process_singleton_->FoundOtherProcessWindow()) {
-      // It seems that we don't need to run the experiment since chrome
-      // in the same profile is already running.
-      VLOG(1) << "Retention experiment not required";
-      return TryChromeDialogView::NOT_NOW;
-    }
+    // and has lauched chrome to show the experiment UI. It is guaranteed that
+    // no other Chrome is currently running as the process singleton was
+    // sucessfully grabbed above.
     int try_chrome_int;
     base::StringToInt(try_chrome, &try_chrome_int);
     TryChromeDialogView::Result answer =
         TryChromeDialogView::Show(try_chrome_int, process_singleton_.get());
     if (answer == TryChromeDialogView::NOT_NOW)
       return chrome::RESULT_CODE_NORMAL_EXIT_CANCEL;
     if (answer == TryChromeDialogView::UNINSTALL_CHROME)
       return chrome::RESULT_CODE_NORMAL_EXIT_EXP2;
     // At this point the user is willing to try chrome again.
     if (answer == TryChromeDialogView::TRY_CHROME_AS_DEFAULT) {
@@ skipping 583 matching lines @@
     if (base::win::GetVersion() <= base::win::VERSION_XP)
       uma_name += "_XP";
 
     uma_name += "_PreRead_";
     uma_name += pre_read_percentage;
     AddPreReadHistogramTime(uma_name.c_str(), time);
   }
 #endif
 #endif
 }