Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/child/site_isolation_stats_gatherer_browsertest.cc

Index: content/child/site_isolation_stats_gatherer_browsertest.cc
diff --git a/content/child/site_isolation_stats_gatherer_browsertest.cc b/content/child/site_isolation_stats_gatherer_browsertest.cc
index d37c97ad568bc5fb40b48b94d21e6eb5eec41974..852ddabe0454d9294114a97f7658e068699aa16d 100644
--- a/content/child/site_isolation_stats_gatherer_browsertest.cc
+++ b/content/child/site_isolation_stats_gatherer_browsertest.cc
@@ -150,8 +150,8 @@ IN_PROC_BROWSER_TEST_F(SiteIsolationStatsGathererBrowserTest,
 
     bool was_blocked;
     ASSERT_TRUE(ExecuteScriptAndExtractBool(
-        shell()->web_contents(),
-        base::StringPrintf("sendRequest(\"%s\");", resource), &was_blocked));
+        shell(), base::StringPrintf("sendRequest(\"%s\");", resource),
+        &was_blocked));
     ASSERT_FALSE(was_blocked);
 
     InspectHistograms(histograms, true, resource);
@@ -174,8 +174,8 @@ IN_PROC_BROWSER_TEST_F(SiteIsolationStatsGathererBrowserTest,
 
     bool was_blocked;
     ASSERT_TRUE(ExecuteScriptAndExtractBool(
-        shell()->web_contents(),
-        base::StringPrintf("sendRequest(\"%s\");", resource), &was_blocked));
+        shell(), base::StringPrintf("sendRequest(\"%s\");", resource),
+        &was_blocked));
     ASSERT_FALSE(was_blocked);
 
     InspectHistograms(histograms, false, resource);