headless: Require the user to pass in an initial URL

headless/test/headless_browser_test.h

Index: headless/test/headless_browser_test.h
diff --git a/headless/test/headless_browser_test.h b/headless/test/headless_browser_test.h
index f46fb90ba60c74f6867b391d9008f3da5d4bf88c..f4875a217c464a7189d7c6116ddd0c8d5591fdba 100644
--- a/headless/test/headless_browser_test.h
+++ b/headless/test/headless_browser_test.h
@@ -5,14 +5,24 @@
 #ifndef HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 #define HEADLESS_TEST_HEADLESS_BROWSER_TEST_H_
 
+#include <memory>
 #include "content/public/test/browser_test_base.h"
 #include "headless/public/headless_browser.h"
 
+namespace base {
+class RunLoop;
+}
+
 namespace headless {
 class HeadlessWebContents;
 
 // Base class for tests which require a full instance of the headless browser.
 class HeadlessBrowserTest : public content::BrowserTestBase {
+ public:
+  // Notify that an asynchronous test is now complete and the test runner should
+  // exit.
+  void FinishAsynchronousTest();
+
  protected:
   HeadlessBrowserTest();
   ~HeadlessBrowserTest() override;
@@ -27,15 +37,20 @@ class HeadlessBrowserTest : public content::BrowserTestBase {
   // pumps) cannot be set via this method.
   void SetBrowserOptions(const HeadlessBrowser::Options& options);
 
-  // Navigate to |url| and wait for the document load to complete.
-  bool NavigateAndWaitForLoad(HeadlessWebContents* web_contents,
-                              const GURL& url);
+  // Run an asynchronous test in a nested run loop. The caller should call
+  // FinishAsynchronousTest() to notify that the test should finish.
+  void RunAsynchronousTest();
+
+  // Synchronously waits for a tab to finish loading.
+  bool WaitForLoad(HeadlessWebContents* web_contents);
 
  protected:
   // Returns the browser for the test.
   HeadlessBrowser* browser() const;
 
  private:
+  std::unique_ptr<base::RunLoop> run_loop_;
+
   DISALLOW_COPY_AND_ASSIGN(HeadlessBrowserTest);
 };