Implement {Start,Stop}CapturingKeyStrokes for Instant.

chrome/common/render_messages.h

 // 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.
 
 // Multiply-included file, no traditional include guard.
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
@@ skipping 603 matching lines @@
 IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_SetSuggestions,
                     int /* page_id */,
                     std::vector<InstantSuggestion> /* suggestions */)
 
 // Sent by the Instant preview indicating whether the page supports the Instant
 // API or not (http://dev.chromium.org/searchbox).
 IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_InstantSupportDetermined,
                     int /* page_id */,
                     bool /* result */)
 
+IPC_MESSAGE_ROUTED2(ChromeViewHostMsg_OnWebSearchBoxFocusChange,
+                    int /* page_id */,
+                    bool /* is_focused */)
+
 // Sent by the Instant preview asking to show itself with the given height.
 IPC_MESSAGE_ROUTED4(ChromeViewHostMsg_ShowInstantPreview,
                     int /* page_id */,
                     InstantShownReason /* reason */,
                     int /* height */,
                     InstantSizeUnits /* units */)
 
 // The currently displayed PDF has an unsupported feature.
 IPC_MESSAGE_ROUTED0(ChromeViewHostMsg_PDFHasUnsupportedFeature)
 
@@ skipping 17 matching lines @@
 // previous SetCookie message to be processed.
 IPC_SYNC_MESSAGE_ROUTED2_1(ChromeViewHostMsg_GetCookies,
                            GURL /* url */,
                            GURL /* first_party_for_cookies */,
                            std::string /* cookies */)
 
 // Provide the browser process with current renderer framerate.
 IPC_MESSAGE_CONTROL2(ChromeViewHostMsg_FPS,
                      int /* routing id */,
                      float /* frames per second */)