Flag-file added for rollback reset option.

As far as update engine that process Rollback requests requires rootfs verification, we're unable to set usual flag for testing Rollback option.

So existence of /tmp/enable_rollback_ui.flag file is the new flag for Rollback reset option.

BUG=368860

Review URL: https://codereview.chromium.org/292973005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272840 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/ui/webui/chromeos/login/reset_screen_handler.cc

@@ -6,7 +6,13 @@
 
 #include <string>
 
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/callback.h"
 #include "base/command_line.h"
+#include "base/file_util.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram.h"
 #include "base/prefs/pref_service.h"
 #include "base/values.h"
@@ -20,6 +26,7 @@
 #include "chromeos/dbus/power_manager_client.h"
 #include "chromeos/dbus/session_manager_client.h"
 #include "chromeos/dbus/update_engine_client.h"
+#include "content/public/browser/browser_thread.h"
 #include "grit/browser_resources.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
@@ -34,6 +41,13 @@ const char kResetScreen[] = "reset";
 
 const int kErrorUIStateRollback = 7;
 
+static const char kRollbackFlagFile[] = "/tmp/.enable_rollback_ui";
+
+void CheckRollbackFlagFileExists(bool *file_exists) {
+  DCHECK(content::BrowserThread::GetBlockingPool()->RunsTasksOnCurrentThread());
+  *file_exists = base::PathExists(base::FilePath(kRollbackFlagFile));
+}
+
 }  // namespace
 
 namespace chromeos {
@@ -94,6 +108,10 @@ void ResetScreenHandler::Show() {
     return;
   }
 
+  ChooseAndApplyShowScenario();
+}
+
+void ResetScreenHandler::ChooseAndApplyShowScenario() {
   PrefService* prefs = g_browser_process->local_state();
   restart_required_ = !CommandLine::ForCurrentProcess()->HasSwitch(
       switches::kFirstExecAfterBoot);
@@ -101,12 +119,34 @@ void ResetScreenHandler::Show() {
   rollback_available_ = false;
   if (!restart_required_)  // First exec after boot.
     reboot_was_requested_ = prefs->GetBoolean(prefs::kFactoryResetRequested);
-  if (!CommandLine::ForCurrentProcess()->HasSwitch(
+
+  // Check Rollback flag-file.
+  scoped_ptr<bool> file_exists(new bool(false));
+  base::Closure checkfile_closure = base::Bind(
+      &CheckRollbackFlagFileExists,
+      base::Unretained(file_exists.get()));
+  base::Closure on_check_done = base::Bind(
+      &ResetScreenHandler::OnRollbackFlagFileCheckDone,
+      weak_ptr_factory_.GetWeakPtr(),
+      base::Passed(file_exists.Pass()));
+  if (!content::BrowserThread::PostBlockingPoolTaskAndReply(
+          FROM_HERE,
+          checkfile_closure,
+          on_check_done)) {
+    LOG(WARNING) << "Failed to check flag file for Rollback reset option";
+    on_check_done.Run();
+  }
+}
+
+void ResetScreenHandler::OnRollbackFlagFileCheckDone(
+    scoped_ptr<bool> file_exists) {
+  if (!file_exists && !CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kEnableRollbackOption)) {
     rollback_available_ = false;
     ShowWithParams();
   } else if (!restart_required_ && reboot_was_requested_) {
     // First exec after boot.
+    PrefService* prefs = g_browser_process->local_state();
     rollback_available_ = prefs->GetBoolean(prefs::kRollbackRequested);
     ShowWithParams();
   } else {

chrome/browser/ui/webui/chromeos/login/reset_screen_handler.h

@@ -50,6 +50,8 @@ class ResetScreenHandler : public ResetScreenActor,
   void HandleOnPowerwash(bool rollback_checked);
   void HandleOnLearnMore();
 
+  void ChooseAndApplyShowScenario();
+  void OnRollbackFlagFileCheckDone(scoped_ptr<bool> file_exists);
   void ShowWithParams();
 
   Delegate* delegate_;