PlzNavigate: properly execute BeforeUnload on renderer initiated navigations

content/renderer/render_frame_impl.cc

 // 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.
 
 #include "content/renderer/render_frame_impl.h"
 
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 1496 matching lines @@
 
 void RenderFrameImpl::OnBeforeUnload() {
   TRACE_EVENT1("navigation", "RenderFrameImpl::OnBeforeUnload",
                "id", routing_id_);
   // TODO(creis): Right now, this is only called on the main frame.  Make the
   // browser process send dispatchBeforeUnloadEvent to every frame that needs
   // it.
   CHECK(!frame_->parent());
 
   base::TimeTicks before_unload_start_time = base::TimeTicks::Now();
-  bool proceed = frame_->dispatchBeforeUnloadEvent();
+
+  // TODO(clamy): Pass the right value for is_reload here.

[dcheng, 2016/05/03 21:34:30]

Let's fix this in this CL as well: since this is somewhat web-visible, we should
try not to break it. It shouldn't be too hard to add this parameter to
FrameMsg_BeforeUnload.

[clamy, 2016/05/04 13:50:15]

Done.

+  blink::WebLocalFrame::BeforeUnloadReturnValue return_value =
+      frame_->dispatchBeforeUnloadEvent(false);
+  if (return_value ==
+      blink::WebLocalFrame::BeforeUnloadReturnValue::FrameDestroyed) {

[dcheng, 2016/05/03 21:34:30]

Let's just use weak_factory_.GetWeakPtr() to detect this condition. Then we
won't need the enum at all, and the code will look simpler. Some other things
that run script hold a |weak_self| pointer to check if |this| is still live.

[clamy, 2016/05/04 13:50:15]

Done.

+    // Return as the frame was destroyed by the BeforeUnload event.
+    return;
+  }
+
   base::TimeTicks before_unload_end_time = base::TimeTicks::Now();
-  Send(new FrameHostMsg_BeforeUnload_ACK(routing_id_, proceed,
-                                         before_unload_start_time,
-                                         before_unload_end_time));
+  Send(new FrameHostMsg_BeforeUnload_ACK(
+      routing_id_,
+      return_value == blink::WebLocalFrame::BeforeUnloadReturnValue::Proceed,
+      before_unload_start_time, before_unload_end_time));
 }
 
 void RenderFrameImpl::OnSwapOut(
     int proxy_routing_id,
     bool is_loading,
     const FrameReplicationState& replicated_frame_state) {
   TRACE_EVENT1("navigation", "RenderFrameImpl::OnSwapOut", "id", routing_id_);
   RenderFrameProxy* proxy = NULL;
 
   // This codepath should only be hit for subframes when in --site-per-process.
@@ skipping 3313 matching lines @@
       // Must be a JavaScript navigation, which appears as "other".
       info.navigationType == blink::WebNavigationTypeOther;
 
   if (is_fork) {
     // Open the URL via the browser, not via WebKit.
     OpenURL(url, Referrer(), info.defaultPolicy,
             info.replacesCurrentHistoryItem, false);
     return blink::WebNavigationPolicyIgnore;
   }
 
+  // Execute the BeforeUnload event. If asked not to proceed or the frame is
+  // destroyed, ignore the navigation. There is no need to execute the
+  // BeforeUnload event during a redirect, since it was already executed at the
+  // start of the navigation.
+  if (!is_redirect && (!IsBrowserSideNavigationEnabled() ||
+                       info.urlRequest.checkForBrowserSideNavigation())) {
+    // PlzNavigate: this is not executed when commiting the navigation.
+    if (frame_->dispatchBeforeUnloadEvent(info.navigationType ==
+                                          blink::WebNavigationTypeReload) !=
+        blink::WebLocalFrame::BeforeUnloadReturnValue::Proceed) {
+      return blink::WebNavigationPolicyIgnore;
+    }
+  }
+
   // PlzNavigate: if the navigation is not synchronous, send it to the browser.
   // This includes navigations with no request being sent to the network stack.
   if (IsBrowserSideNavigationEnabled() &&
       info.urlRequest.checkForBrowserSideNavigation() &&
       ShouldMakeNetworkRequestForURL(url)) {
     BeginNavigation(&info.urlRequest, info.replacesCurrentHistoryItem,
                     info.isClientRedirect);
     return blink::WebNavigationPolicyHandledByClient;
   }
 
@@ skipping 731 matching lines @@
     CHECK_EQ(-1, render_view_->history_list_offset_);
     CHECK_EQ(0, render_view_->history_list_length_);
   }
 }
 
 void RenderFrameImpl::BeginNavigation(blink::WebURLRequest* request,
                                       bool should_replace_current_entry,
                                       bool is_client_redirect) {
   CHECK(IsBrowserSideNavigationEnabled());
   DCHECK(request);
-  // TODO(clamy): Execute the beforeunload event.
 
   // Note: At this stage, the goal is to apply all the modifications the
   // renderer wants to make to the request, and then send it to the browser, so
   // that the actual network request can be started. Ideally, all such
   // modifications should take place in willSendRequest, and in the
   // implementation of willSendRequest for the various InspectorAgents
   // (devtools).
   //
   // TODO(clamy): Apply devtools override.
   // TODO(clamy): Make sure that navigation requests are not modified somewhere
@@ skipping 416 matching lines @@
                                     int match_count,
                                     int ordinal,
                                     const WebRect& selection_rect,
                                     bool final_status_update) {
   Send(new FrameHostMsg_Find_Reply(routing_id_, request_id, match_count,
                                    selection_rect, ordinal,
                                    final_status_update));
 }
 
 }  // namespace content