Extend the ToRenderFrameHost magic to FrameTreeNode* and Shell*

content/browser/database_browsertest.cc

Index: content/browser/database_browsertest.cc
diff --git a/content/browser/database_browsertest.cc b/content/browser/database_browsertest.cc
index e38e41737446cd341cc3ca4475fd5a4a2ccc66bc..35160299b629aa6c1cf0b205e9af5e2d60c9a5e7 100644
--- a/content/browser/database_browsertest.cc
+++ b/content/browser/database_browsertest.cc
@@ -26,10 +26,7 @@ class DatabaseTest : public ContentBrowserTest {
                                const std::string& script,
                                const std::string& result) {
     std::string data;
-    ASSERT_TRUE(ExecuteScriptAndExtractString(
-        shell->web_contents(),
-        script,
-        &data));
+    ASSERT_TRUE(ExecuteScriptAndExtractString(shell, script, &data));
     ASSERT_EQ(data, result);
   }
 
@@ -63,10 +60,7 @@ class DatabaseTest : public ContentBrowserTest {
 
   bool HasTable(Shell* shell) {
     std::string data;
-    CHECK(ExecuteScriptAndExtractString(
-        shell->web_contents(),
-        "getRecords()",
-        &data));
+    CHECK(ExecuteScriptAndExtractString(shell, "getRecords()", &data));
     return data != "getRecords error: [object SQLError]";
   }
 };