PlzNavigate: properly execute BeforeUnload on renderer initiated navigations

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 626 matching lines @@
 
 // Tells the renderer to perform the specified navigation, interrupting any
 // existing navigation.
 IPC_MESSAGE_ROUTED3(FrameMsg_Navigate,
                     content::CommonNavigationParams, /* common_params */
                     content::StartNavigationParams,  /* start_params */
                     content::RequestNavigationParams /* request_params */)
 
 // Instructs the renderer to invoke the frame's beforeunload event handler.
 // Expects the result to be returned via FrameHostMsg_BeforeUnload_ACK.
-IPC_MESSAGE_ROUTED0(FrameMsg_BeforeUnload)
+IPC_MESSAGE_ROUTED1(FrameMsg_BeforeUnload, bool /* is_reload */)
 
 // Instructs the frame to swap out for a cross-site transition, including
 // running the unload event handler and creating a RenderFrameProxy with the
 // given |proxy_routing_id|. Expects a SwapOut_ACK message when finished.
 IPC_MESSAGE_ROUTED3(FrameMsg_SwapOut,
                     int /* proxy_routing_id */,
                     bool /* is_loading */,
                     content::FrameReplicationState /* replication_state */)
 
 // Instructs the frame to stop the load in progress, if any.
@@ skipping 788 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.