Add KeepaliveImpulse to extension process manager.

extensions/common/switches.cc

Index: extensions/common/switches.cc
diff --git a/extensions/common/switches.cc b/extensions/common/switches.cc
index 82222c428d0ec92c4751e631568ff630a73ad174..5d50344671261dbb2267b9bfd8c649019a611a22 100644
--- a/extensions/common/switches.cc
+++ b/extensions/common/switches.cc
@@ -34,12 +34,12 @@ const char kEnableExperimentalExtensionApis[] =
 // them in the chrome:extensions page.
 const char kErrorConsole[] = "error-console";
 
-// The time in seconds that an extension event page can be idle before it
+// The time in milliseconds that an extension event page can be idle before it

[scheib, 2013/12/02 21:22:38]

Done.

 // is shut down.
 const char kEventPageIdleTime[]             = "event-page-idle-time";
 
-// The time in seconds that an extension event page has between being notified
-// of its impending unload and that unload happening.
+// The time in milliseconds that an extension event page has between being
+// notified of its impending unload and that unload happening.
 const char kEventPageSuspendingTime[]       = "event-page-unloading-time";
 
 // Enables extensions running scripts on chrome:// URLs.