Add KeepaliveImpulse to extension process manager.

chrome/browser/extensions/extension_context_menu_browsertest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/strings/utf_string_conversions.h"
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/extensions/extension_browsertest.h"
 #include "chrome/browser/extensions/extension_service.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/browser/extensions/extension_test_message_listener.h"
@@ skipping 591 matching lines @@
   TestEnabledContextMenu(true);
   TestEnabledContextMenu(false);
 }
 
 class ExtensionContextMenuBrowserLazyTest :
     public ExtensionContextMenuBrowserTest {
   virtual void SetUpCommandLine(CommandLine* command_line) OVERRIDE {
     ExtensionContextMenuBrowserTest::SetUpCommandLine(command_line);
     // Set shorter delays to prevent test timeouts.
     command_line->AppendSwitchASCII(
-        extensions::switches::kEventPageIdleTime, "0");
+        extensions::switches::kEventPageIdleTime, "1");
     command_line->AppendSwitchASCII(
         extensions::switches::kEventPageSuspendingTime, "0");
   }
 };
 
 IN_PROC_BROWSER_TEST_F(ExtensionContextMenuBrowserLazyTest, EventPage) {
   GURL about_blank("about:blank");
   LazyBackgroundObserver page_complete;
   const extensions::Extension* extension = LoadContextMenuExtension(
       "event_page");
@@ skipping 36 matching lines @@
   ASSERT_TRUE(LoadContextMenuExtensionIncognito("incognito"));
 
   // Wait for the extension's processes to tell us they've created an item.
   ASSERT_TRUE(created.WaitUntilSatisfied());
   ASSERT_TRUE(created_incognito.WaitUntilSatisfied());
   ASSERT_EQ(2u, GetItems().size());
 
   browser()->profile()->DestroyOffTheRecordProfile();
   ASSERT_EQ(1u, GetItems().size());
 }