Fix a crash in TestingAutomationProvider::GetTabInfo on ChromeOS.

chrome/browser/automation/testing_automation_provider.cc

Index: chrome/browser/automation/testing_automation_provider.cc
diff --git a/chrome/browser/automation/testing_automation_provider.cc b/chrome/browser/automation/testing_automation_provider.cc
index 4e8e4bc0986b3a98aee222d9df220157cae98431..6216b1bf2e1be7e29c6943f3a5f508b3f8b05d35 100644
--- a/chrome/browser/automation/testing_automation_provider.cc
+++ b/chrome/browser/automation/testing_automation_provider.cc
@@ -6668,6 +6668,10 @@ void TestingAutomationProvider::GetTabInfo(
   std::string error;
   if (GetBrowserAndTabFromJSONArgs(args, &browser, &tab, &error)) {
     NavigationEntry* entry = tab->GetController().GetActiveEntry();
+    if (!entry) {
+      reply.SendError("Unable to get active navigation entry");
+      return;
+    }
     DictionaryValue dict;
     dict.SetString("title", entry->GetTitleForDisplay(""));
     dict.SetString("url", entry->GetVirtualURL().spec());