network service: pass PlzNavigate resulting data via mojo data pipe

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 889 matching lines @@
 #else
 IPC_MESSAGE_ROUTED2(FrameMsg_SelectPopupMenuItems,
                     bool /* user canceled the popup */,
                     std::vector<int> /* selected indices */)
 #endif
 #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,
-                    content::ResourceResponseHead,    /* response */
-                    GURL,                             /* stream_url */
-                    content::CommonNavigationParams,  /* common_params */
-                    content::RequestNavigationParams  /* request_params */)
+// response. When --enable-network-service is in effect, |stream_url| is not
+// used, and instead the data is passed to the renderer in |handle|.
+IPC_MESSAGE_ROUTED5(FrameMsg_CommitNavigation,
+                    content::ResourceResponseHead,   /* response */
+                    GURL,                            /* stream_url */
+                    mojo::DataPipeConsumerHandle,    /* handle */
+                    content::CommonNavigationParams, /* common_params */
+                    content::RequestNavigationParams /* request_params */)
 
 // 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 721 matching lines @@
                     int /* nfr_request_id */,
                     float /* distance */)
 
 IPC_MESSAGE_ROUTED0(FrameHostMsg_NavigationHandledByEmbedder)
 #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.