Fix some unit_tests under 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 f78cde14b7ae83a222827b29aebdf6444e1d1b3f..6947b9ab4ba1225067a076d3a8057f6dd996351b 100644
--- a/content/test/test_render_frame_host.cc
+++ b/content/test/test_render_frame_host.cc
@@ -18,7 +18,7 @@
 #include "content/public/browser/stream_handle.h"
 #include "content/public/common/browser_side_navigation_policy.h"
 #include "content/public/common/url_constants.h"
-#include "content/test/browser_side_navigation_test_utils.h"
+#include "content/public/test/browser_side_navigation_test_utils.h"
 #include "content/test/test_navigation_url_loader.h"
 #include "content/test/test_render_view_host.h"
 #include "mojo/public/cpp/bindings/interface_request.h"
@@ -218,6 +218,13 @@ void TestRenderFrameHost::SimulateNavigationStop() {
   }
 }
 
+void TestRenderFrameHost::SimulateUnloading() {
+  if (!IsBrowserSideNavigationEnabled() ||
+      frame_tree_node()->navigation_request()) {
+    PrepareForCommit();
+  }
+}
+
 void TestRenderFrameHost::SetContentsMimeType(const std::string& mime_type) {
   contents_mime_type_ = mime_type;
 }