browser: Start moving application_lifetime.h functions into chrome namespace.

chrome/browser/browser_process_impl.cc

Index: chrome/browser/browser_process_impl.cc
diff --git a/chrome/browser/browser_process_impl.cc b/chrome/browser/browser_process_impl.cc
index 8986afa03b7368bf362580f77008d0a60acd357c..db96a1d7f24bb5440fea02db7f647dc58385a470 100644
--- a/chrome/browser/browser_process_impl.cc
+++ b/chrome/browser/browser_process_impl.cc
@@ -954,7 +954,7 @@ void BrowserProcessImpl::ApplyAllowCrossOriginAuthPromptPolicy() {
 bool BrowserProcessImpl::CanAutorestartForUpdate() const {
   // Check if browser is in the background and if it needs to be restarted to
   // apply a pending update.
-  return BrowserList::size() == 0 && browser::WillKeepAlive() &&
+  return BrowserList::empty() && chrome::WillKeepAlive() &&
          upgrade_util::IsUpdatePendingRestart();
 }