Instant: Use only one hidden WebContents per profile.

chrome/common/chrome_notification_types.h

Index: chrome/common/chrome_notification_types.h
diff --git a/chrome/common/chrome_notification_types.h b/chrome/common/chrome_notification_types.h
index c1508380b12316f34735a9f2ca4f62a1bc0e8d6d..70423d4c60317a44512de4c1b17b9ddde05ff9b1 100644
--- a/chrome/common/chrome_notification_types.h
+++ b/chrome/common/chrome_notification_types.h
@@ -1101,24 +1101,15 @@ enum NotificationType {
   // Send when a context menu is closed.
   NOTIFICATION_RENDER_VIEW_CONTEXT_MENU_CLOSED,
 
-  // Sent each time the InstantController is updated.
-  NOTIFICATION_INSTANT_CONTROLLER_UPDATED,
+  // Sent each time a search query is sent to an Instant page.
+  NOTIFICATION_INSTANT_UPDATED,
 
   // Sent when an Instant overlay is committed. The Source is the WebContents
   // containing the committed overlay.
   NOTIFICATION_INSTANT_COMMITTED,
 
-  // Sent when the Instant Controller determines whether the overlay supports
-  // the Instant API or not.
-  NOTIFICATION_INSTANT_OVERLAY_SUPPORT_DETERMINED,
-
-  // Sent when the Instant Controller determines whether the NTP supports the
-  // Instant API or not.
-  NOTIFICATION_INSTANT_NTP_SUPPORT_DETERMINED,
-
-  // Sent when the Instant Controller has sent the Most Visited Items to the
-  // renderer.
-  NOTIFICATION_INSTANT_SENT_MOST_VISITED_ITEMS,
+  // Sent when we've determined if a page supports Instant. Only used in tests.
+  NOTIFICATION_INSTANT_SUPPORT_DETERMINED,
 
   // Sent when the CaptivePortalService checks if we're behind a captive portal.
   // The Source is the Profile the CaptivePortalService belongs to, and the