headless: Require the user to pass in an initial URL

headless/public/headless_browser.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEADLESS_PUBLIC_HEADLESS_BROWSER_H_
 #define HEADLESS_PUBLIC_HEADLESS_BROWSER_H_
 
 #include <memory>
 #include <string>
 
@@ skipping 17 matching lines @@
 class HeadlessWebContents;
 
 // This class represents the global headless browser instance. To get a pointer
 // to one, call |HeadlessBrowserMain| to initiate the browser main loop. An
 // instance of |HeadlessBrowser| will be passed to the callback given to that
 // function.
 class HEADLESS_EXPORT HeadlessBrowser {
  public:
   struct Options;
 
-  // Create a new browser tab. |size| is in physical pixels.
+  // Create a new browser tab which navigates to |initial_url|. |size| is in
+  // physical pixels.
   virtual std::unique_ptr<HeadlessWebContents> CreateWebContents(
+      const GURL& initial_url,
       const gfx::Size& size) = 0;
 
   // Returns a task runner for submitting work to the browser main thread.
   virtual scoped_refptr<base::SingleThreadTaskRunner> BrowserMainThread()
       const = 0;
 
   // Requests browser to stop as soon as possible. |Run| will return as soon as
   // browser stops.
   virtual void Shutdown() = 0;
 
@@ skipping 57 matching lines @@
 // |on_browser_start_callback| callback. Note that since this function executes
 // the main loop, it will only return after HeadlessBrowser::Shutdown() is
 // called, returning the exit code for the process.
 int HeadlessBrowserMain(
     const HeadlessBrowser::Options& options,
     const base::Callback<void(HeadlessBrowser*)>& on_browser_start_callback);
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_HEADLESS_BROWSER_H_