Run unload handlers when navigating to about:blank using PlzNavigate.

content/test/test_render_frame_host.cc

Index: content/test/test_render_frame_host.cc
diff --git a/content/test/test_render_frame_host.cc b/content/test/test_render_frame_host.cc
index 82fcac4f3d66c6b8f80f77e73c641fe0bd9c49e8..d94dce0881c284c5731ce934998ba49f7ab6a1ad 100644
--- a/content/test/test_render_frame_host.cc
+++ b/content/test/test_render_frame_host.cc
@@ -425,6 +425,8 @@ void TestRenderFrameHost::PrepareForCommitWithServerRedirect(
   // PlzNavigate
   NavigationRequest* request = frame_tree_node_->navigation_request();
   CHECK(request);
+  bool have_to_make_network_request = ShouldMakeNetworkRequestForURL(
+      request->common_params().url);
 
   // Simulate a beforeUnload ACK from the renderer if the browser is waiting for
   // it. If it runs it will update the request state.
@@ -433,6 +435,9 @@ void TestRenderFrameHost::PrepareForCommitWithServerRedirect(
         ->SendBeforeUnloadACK(true);
   }
 
+  if (!have_to_make_network_request)
+    return;  // |request| is destructed by now.
+
   CHECK(request->state() == NavigationRequest::STARTED);
 
   TestNavigationURLLoader* url_loader =