content: Make sure the renderer notifies the browser about touch-event handlers properly.

content/common/view_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.
 
 // IPC messages for page rendering.
 // Multiply-included message file, hence no include guard.
 
 #include "base/process.h"
 #include "base/shared_memory.h"
 #include "content/common/content_export.h"
@@ skipping 1750 matching lines @@
                     bool /* pinned_to_right */)
 
 // Notifies that the number of JavaScript scroll handlers changed.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidChangeNumWheelEvents,
                     int /* count */)
 
 // Notifies that the number of JavaScript touch event handlers changed.
 IPC_MESSAGE_ROUTED1(ViewHostMsg_DidChangeNumTouchEvents,
                     int /* count */)
 
+// Notifies whether there are JavaScript touche event handlers or not.
+IPC_MESSAGE_ROUTED1(ViewHostMsg_HasTouchEventHandlers,
+                    bool /* has_handlers */)
+
 // A message from HTML-based UI.  When (trusted) Javascript calls
 // send(message, args), this message is sent to the browser.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_WebUISend,
                     GURL /* source_url */,
                     std::string  /* message */,
                     base::ListValue /* args */)
 
 // A renderer sends this to the browser process when it wants to create a ppapi
 // plugin.  The browser will create the plugin process if necessary, and will
 // return a handle to the channel on success.
@@ skipping 376 matching lines @@
 // (according to the value of is_hung). The browser can give the user the
 // option of killing the plugin.
 IPC_MESSAGE_ROUTED3(ViewHostMsg_PepperPluginHung,
                     int /* plugin_child_id */,
                     FilePath /* path */,
                     bool /* is_hung */)
 
 // Screen was rotated. Dispatched to the onorientationchange javascript API.
 IPC_MESSAGE_ROUTED1(ViewMsg_OrientationChangeEvent,
                     int /* orientation */)