Disable upgrade detector if a Guest window is open.

Current Guest profiles are OffTheRecord and upgrade detection is
disabled when an OTR session is running. But ephemeral Guest profiles
are not OTR and hence not covered.

An extra check for existence of Guest profiles to disable upgrade is
added.

Please see go/ephemeral-guest-profiles for more context.

Bug: 1125474
Change-Id: I1a14f7222bab47ea8385f03e262d2982b53ab749
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2505750
Commit-Queue: Ramin Halavati <rhalavati@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822065}

chrome/browser/upgrade_detector/upgrade_detector.cc

@@ -10,6 +10,7 @@
 #include "base/time/tick_clock.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
+#include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_otr_state.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
@@ -207,10 +208,13 @@ void UpgradeDetector::TriggerCriticalUpdate() {
 
 void UpgradeDetector::CheckIdle() {
   DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
-  // Don't proceed while an off-the-record window is open. The timer will still
-  // keep firing, so this function will get a chance to re-evaluate this.
-  if (chrome::IsOffTheRecordSessionActive())
+  // Don't proceed while an off-the-record or Guest window is open. The timer
+  // will still keep firing, so this function will get a chance to re-evaluate
+  // this.
+  if (chrome::IsOffTheRecordSessionActive() ||
+      BrowserList::GetGuestBrowserCount()) {
     return;
+  }
 
   // CalculateIdleState expects an interval in seconds.
   int idle_time_allowed =