Add ExecuteJavaScriptForTest and make all tests use it

extensions/browser/api/system_storage/system_storage_eject_apitest.cc

Index: extensions/browser/api/system_storage/system_storage_eject_apitest.cc
diff --git a/extensions/browser/api/system_storage/system_storage_eject_apitest.cc b/extensions/browser/api/system_storage/system_storage_eject_apitest.cc
index da9a59d1c4eb997fd1ec44d26f9e0a1f6bce3fd8..bebd66538471eabcbc2916e58ec5b05436429d50 100644
--- a/extensions/browser/api/system_storage/system_storage_eject_apitest.cc
+++ b/extensions/browser/api/system_storage/system_storage_eject_apitest.cc
@@ -58,7 +58,8 @@ class SystemStorageEjectApiTest : public extensions::ShellApiTest {
                                const std::string& js_command,
                                const std::string& ok_message) {
     ExtensionTestMessageListener listener(ok_message, false);
-    host->GetMainFrame()->ExecuteJavaScript(base::ASCIIToUTF16(js_command));
+    host->GetMainFrame()->ExecuteJavaScriptForTests(
+        base::ASCIIToUTF16(js_command));
     EXPECT_TRUE(listener.WaitUntilSatisfied());
   }