Cleanup: Pull some browser keep alive functions into its own file.

chrome/browser/ui/views/auto_keep_alive.cc

Index: chrome/browser/ui/views/auto_keep_alive.cc
diff --git a/chrome/browser/ui/views/auto_keep_alive.cc b/chrome/browser/ui/views/auto_keep_alive.cc
index c7128e983f42d2d346c655574c26f50c22fbd385..4f45affac58ec15cd227b40a7a8c99de29a7b3ae 100644
--- a/chrome/browser/ui/views/auto_keep_alive.cc
+++ b/chrome/browser/ui/views/auto_keep_alive.cc
@@ -4,11 +4,10 @@
 
 #include "chrome/browser/ui/views/auto_keep_alive.h"
 
-#include "chrome/browser/lifetime/application_lifetime.h"
+#include "chrome/browser/lifetime/browser_keep_alive.h"
 #include "chrome/browser/ui/host_desktop.h"
 
-AutoKeepAlive::AutoKeepAlive(gfx::NativeWindow window)
-    : keep_alive_available_(false) {
+AutoKeepAlive::AutoKeepAlive(gfx::NativeWindow window) {
   // In case of aura we want default to be keep alive not available for ash
   // because ash has keep alive set and we don't want additional keep alive
   // count.
@@ -16,12 +15,10 @@ AutoKeepAlive::AutoKeepAlive(gfx::NativeWindow window)
       window ? chrome::GetHostDesktopTypeForNativeWindow(window)
              : chrome::GetActiveDesktop();
   if (desktop_type != chrome::HOST_DESKTOP_TYPE_ASH) {
-    keep_alive_available_ = true;
-    chrome::IncrementKeepAliveCount();
+    keep_alive_.reset(new browser_lifetime::ScopedKeepAlive);
   }
 }
 
 AutoKeepAlive::~AutoKeepAlive() {
-  if (keep_alive_available_)
-    chrome::DecrementKeepAliveCount();
+  keep_alive_.reset();
 }