PROTOTYPE: PlzNavigate: use a Mojo data pipe to stream navigation data to the renderer.

content/common/frame_messages.h

 // Copyright 2013 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 interacting with frames.
 // Multiply-included message file, hence no include guard.
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 778 matching lines @@
 // External popup menus.
 IPC_MESSAGE_ROUTED1(FrameMsg_SelectPopupMenuItem,
                     int /* selected index, -1 means no selection */)
 
 #endif
 
 // PlzNavigate
 // Tells the renderer that a navigation is ready to commit.  The renderer should
 // request |stream_url| to get access to the stream containing the body of the
 // response.
-IPC_MESSAGE_ROUTED4(FrameMsg_CommitNavigation,
+IPC_MESSAGE_ROUTED5(FrameMsg_CommitNavigation,
                     content::ResourceResponseHead,   /* response */
                     GURL,                            /* stream_url */
                     content::CommonNavigationParams, /* common_params */
-                    content::RequestNavigationParams /* request_params */)
+                    content::RequestNavigationParams, /* request_params */
+                    int32_t /* navigation_commit_id */)
 
 // PlzNavigate
 // Tells the renderer that a navigation failed with the error code |error_code|
 // and that the renderer should display an appropriate error page.
 IPC_MESSAGE_ROUTED4(FrameMsg_FailedNavigation,
                     content::CommonNavigationParams,  /* common_params */
                     content::RequestNavigationParams, /* request_params */
                     bool,                             /* stale_copy_in_cache */
                     int                               /* error_code */)
 
@@ skipping 615 matching lines @@
 IPC_MESSAGE_ROUTED3(FrameHostMsg_FindMatchRects_Reply,
                     int /* version */,
                     std::vector<gfx::RectF> /* rects */,
                     gfx::RectF /* active_rect */)
 #endif
 
 // Adding a new message? Stick to the sort order above: first platform
 // independent FrameMsg, then ifdefs for platform specific FrameMsg, then
 // platform independent FrameHostMsg, then ifdefs for platform specific
 // FrameHostMsg.