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

content/common/frame_messages.h

Index: content/common/frame_messages.h
diff --git a/content/common/frame_messages.h b/content/common/frame_messages.h
index 96ecbf4c61c09524565bf75ca4eec65f78097132..0bd074531190bbb7e75aa3e1ad8422ee28ab55ec 100644
--- a/content/common/frame_messages.h
+++ b/content/common/frame_messages.h
@@ -796,11 +796,12 @@ IPC_MESSAGE_ROUTED1(FrameMsg_SelectPopupMenuItem,
 // 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|