Add option to disallow the discarding of a tab that was previously discarded.

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"
 
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 1144 matching lines @@
 
   three_d_observer_.reset(new ThreeDAPIObserver());
 
   // Start the out-of-memory priority manager here so that we give the most
   // amount of time for the other services to start up before we start
   // adjusting the oom priority.
   //
   // On CrOS, it is always enabled. On other platforms, it's behind a flag for
   // now.
 #if defined(OS_CHROMEOS)
-  g_browser_process->GetOomPriorityManager()->Start();
+  g_browser_process->GetOomPriorityManager()->Start(false);
 #elif defined(OS_WIN) || defined(OS_MACOSX)
   const std::string group_name =
       base::FieldTrialList::FindFullName("AutomaticTabDiscarding");
   if (parsed_command_line().HasSwitch(switches::kEnableTabDiscarding) ||
       base::StartsWith(group_name, "Enabled", base::CompareCase::SENSITIVE)) {
-    g_browser_process->GetOomPriorityManager()->Start();
+    g_browser_process->GetOomPriorityManager()->Start(group_name ==

[rkaplow, 2015/09/11 21:07:03]

suggest using StartsWith

[Georges Khalil, 2015/09/14 18:17:48]

Done.

+                                                      "Enabled_Once");
   }
 #endif
 }
 
 void ChromeBrowserMainParts::PostBrowserStart() {
   TRACE_EVENT0("startup", "ChromeBrowserMainParts::PostBrowserStart");
   for (size_t i = 0; i < chrome_extra_parts_.size(); ++i)
     chrome_extra_parts_[i]->PostBrowserStart();
 #if !defined(OS_ANDROID)
   // Allow ProcessSingleton to process messages.
@@ skipping 666 matching lines @@
   chromeos::CrosSettings::Shutdown();
 #endif  // defined(OS_CHROMEOS)
 #endif  // defined(OS_ANDROID)
 }
 
 // Public members:
 
 void ChromeBrowserMainParts::AddParts(ChromeBrowserMainExtraParts* parts) {
   chrome_extra_parts_.push_back(parts);
 }