Adds support for showing the match preview on views. It's behind the

chrome/common/notification_type.h

 // Copyright (c) 2010 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.
 
 #ifndef CHROME_COMMON_NOTIFICATION_TYPE_H_
 #define CHROME_COMMON_NOTIFICATION_TYPE_H_
 #pragma once
 
 // This file describes various types used to describe and filter notifications
 // that pass through the NotificationService.
@@ skipping 375 matching lines @@
 
     // This notification is sent when TabContents::SetAppExtension is invoked.
     // The source is the TabContents SetAppExtension was invoked on.
     TAB_CONTENTS_APPLICATION_EXTENSION_CHANGED,
 
     // A RenderViewHost was created for a TabContents. The source is the
     // associated TabContents, and the details is the RenderViewHost
     // pointer.
     RENDER_VIEW_HOST_CREATED_FOR_TAB,
 
+    // Sent when MatchPreview creates the preview TabContents. The source is the
+    // TabContents the MatchPreview is associated with.
+    MATCH_PREVIEW_TAB_CONTENTS_CREATED,
+
     // Stuff inside the tabs ---------------------------------------------------
 
     // This message is sent after a constrained window has been closed.  The
     // source is a Source<ConstrainedWindow> with a pointer to the closed child
     // window.  (The pointer isn't usable, except for identification.) No
     // details are expected.
     CWINDOW_CLOSED,
 
     // Indicates that a RenderProcessHost was created and its handle is now
     // available. The source will be the RenderProcessHost that corresponds to
@@ skipping 737 matching lines @@
 };
 
 inline bool operator==(NotificationType::Type a, NotificationType b) {
   return a == b.value;
 }
 inline bool operator!=(NotificationType::Type a, NotificationType b) {
   return a != b.value;
 }
 
 #endif  // CHROME_COMMON_NOTIFICATION_TYPE_H_