Add commands to manage tabs and contexts to Browser Domain

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>
 #include <unordered_map>
@@ skipping 20 matching lines @@
 namespace headless {
 
 // 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;
 
+  class HEADLESS_EXPORT Observer {

[Sami, 2016/07/04 15:28:54]

Could we instead add a getter that turns a target id into a HeadlessWebContents
object? If we want these to be events, we could probably add them to the
devtools browser domain.

[alex clarke (OOO till 29th), 2016/07/04 16:33:59]

I only really added it for testing when I had a different way of closing the
page which made it async. I think we can live without it now.

+   public:
+    // All the following notifications will be called on browser main thread.
+
+    virtual void HeadlessWebContentsCreated(HeadlessWebContents* web_contents) {
+    }
+
+    // Note |web_contents| has been deleted, do not dereference.
+    virtual void HeadlessWebContentsDestroyed(
+        HeadlessWebContents* web_contents) {}
+
+   protected:
+    Observer() {}
+    virtual ~Observer() {}
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(Observer);
+  };
+
+  // Add or remove an observer to receive events from this HeadlessBrowser.
+  // |observer| must outlive this class or be removed prior to being destroyed.
+  virtual void AddObserver(Observer* observer) = 0;
+  virtual void RemoveObserver(Observer* observer) = 0;
+
   // Open a new tab. Returns a builder object which can be used to set
   // properties for the new tab.
   virtual HeadlessWebContents::Builder CreateWebContentsBuilder() = 0;
 
   // Deprecated. Use CreateWebContentsBuilder() instead.
   virtual HeadlessWebContents* CreateWebContents(const GURL& initial_url,
                                                  const gfx::Size& size) = 0;
 
   virtual std::vector<HeadlessWebContents*> GetAllWebContents() = 0;
 
@@ skipping 116 matching lines @@
 // the main loop, it will only return after HeadlessBrowser::Shutdown() is
 // called, returning the exit code for the process. It is not possible to
 // initialize the browser again after it has been torn down.
 int HeadlessBrowserMain(
     HeadlessBrowser::Options options,
     const base::Callback<void(HeadlessBrowser*)>& on_browser_start_callback);
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_HEADLESS_BROWSER_H_