[headless] AddWindowTreeClient

headless/public/headless_browser.h

Index: headless/public/headless_browser.h
diff --git a/headless/public/headless_browser.h b/headless/public/headless_browser.h
index 011017471e1f86e5d803ea1bdd0ce14b4816d71e..b8c4f93d821328c03701eb9c34c1aee3b1fc8466 100644
--- a/headless/public/headless_browser.h
+++ b/headless/public/headless_browser.h
@@ -37,9 +37,13 @@ class HEADLESS_EXPORT HeadlessBrowser {
 
   // 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;
+  // We require the user to pass an initial URL to ensure that the renderer
+  // gets initialized and eventually becomes ready to be inspected. See
+  // HeadlessWebContents::Observer::DevToolsTargetReady.
+  virtual HeadlessWebContents* CreateWebContents(const GURL& initial_url,
+                                                 const gfx::Size& size) = 0;
+
+  virtual std::vector<HeadlessWebContents*> GetAllWebContents() = 0;
 
   // Returns a task runner for submitting work to the browser main thread.
   virtual scoped_refptr<base::SingleThreadTaskRunner> BrowserMainThread()