Add a "Keepalive count" column to Task Manager.

chrome/app/generated_resources.grd

Index: chrome/app/generated_resources.grd
diff --git a/chrome/app/generated_resources.grd b/chrome/app/generated_resources.grd
index 28e8a17f6f649b114f7ec1f82d78828a22841293..83511026e195fe8e6afe849b0b4909eab1eb9f4f 100644
--- a/chrome/app/generated_resources.grd
+++ b/chrome/app/generated_resources.grd
@@ -3394,6 +3394,9 @@ From <ph name="DOWNLOAD_DOMAIN">$3<ex>example.com</ex></ph>
           <message name="IDS_TASK_MANAGER_MEMORY_STATE_COLUMN" desc="Task manager memory state column.  Shows the memory coordinator's state of a process">
             Memory state
           </message>
+          <message name="IDS_TASK_MANAGER_KEEPALIVE_COUNT_COLUMN" desc="Task manager keepalive count column.  Shows the keepalive count of background pages">
+            Keepalive count
+          </message>
         </if>
         <if expr="use_titlecase">
           <message name="IDS_TASK_MANAGER_KILL" desc="The caption of the Task Manager kill button">