Prevent creating background pages for non-incognito profile in Guest mode

chrome/browser/extensions/chrome_extensions_browser_client.cc

Index: chrome/browser/extensions/chrome_extensions_browser_client.cc
diff --git a/chrome/browser/extensions/chrome_extensions_browser_client.cc b/chrome/browser/extensions/chrome_extensions_browser_client.cc
index 69b3a96e11a7ad6a42c69b50c0f4f93c17142572..f6b129246f6011c42ab595d6cccefca3204a14f1 100644
--- a/chrome/browser/extensions/chrome_extensions_browser_client.cc
+++ b/chrome/browser/extensions/chrome_extensions_browser_client.cc
@@ -18,6 +18,10 @@
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/pref_names.h"
 
+#if defined(OS_CHROMEOS)
+#include "chromeos/chromeos_switches.h"
+#endif
+
 namespace extensions {
 
 ChromeExtensionsBrowserClient::ChromeExtensionsBrowserClient() {}
@@ -89,6 +93,21 @@ bool ChromeExtensionsBrowserClient::DeferLoadingBackgroundHosts(
 #endif
 }
 
+bool ChromeExtensionsBrowserClient::IsBackgroundPageAllowed(
+    content::BrowserContext* context) const {
+#if defined(OS_CHROMEOS)
+  // Returns true if current session is Chrome OS Guest mode session and current
+  // browser context is *not* off-the-record. Such context is artificial and
+  // background page shouldn't be created in it.
+  const CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(chromeos::switches::kGuestSession) &&
+      !context->IsOffTheRecord()) {
+    return false;
+  }
+#endif
+  return true;
+}
+
 bool ChromeExtensionsBrowserClient::DidVersionUpdate(
     content::BrowserContext* context) {
   Profile* profile = static_cast<Profile*>(context);