Stop trusting the sign-in process if it manages to navigate to another URL.

chrome/browser/signin/signin_manager.cc

Index: chrome/browser/signin/signin_manager.cc
diff --git a/chrome/browser/signin/signin_manager.cc b/chrome/browser/signin/signin_manager.cc
index 68479d4fa761e2c9c6f15fb3bfab8d704da17a44..a9acf8b0a8e4172e9d5cf63de254ad439056a2b4 100644
--- a/chrome/browser/signin/signin_manager.cc
+++ b/chrome/browser/signin/signin_manager.cc
@@ -103,6 +103,10 @@ void SigninManager::SetSigninProcess(int process_id) {
                  content::Source<content::RenderProcessHost>(process));
 }
 
+void SigninManager::ClearSigninProcess() {
+  signin_process_id_ = kInvalidProcessId;
+}
+
 bool SigninManager::IsSigninProcess(int process_id) const {
   return process_id == signin_process_id_;
 }