Adding Navigation Throttles to DevTools

content/browser/devtools/page_navigation_throttle.h

+// Copyright 2016 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 CONTENT_BROWSER_DEVTOOLS_PAGE_NAVIGATION_THROTTLE_H_
+#define CONTENT_BROWSER_DEVTOOLS_PAGE_NAVIGATION_THROTTLE_H_
+
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "content/public/browser/navigation_throttle.h"
+
+namespace content {
+namespace devtools {
+namespace page {
+class PageHandler;
+}  // namespace page
+
+// Used to allow the DevTools client to optionally cancel navigations via the
+// Page.setControlNavigations and Page.processNavigation commands.
+class PageNavigationThrottle : public content::NavigationThrottle {
+ public:
+  PageNavigationThrottle(base::WeakPtr<page::PageHandler> page_handler,
+                         int navigation_id,
+                         content::NavigationHandle* navigation_handle);
+  ~PageNavigationThrottle() override;
+
+  // content::NavigationThrottle implementation:
+  NavigationThrottle::ThrottleCheckResult WillStartRequest() override;
+  NavigationThrottle::ThrottleCheckResult WillRedirectRequest() override;
+
+  int navigation_id() const { return navigation_id_; }
+
+  // Tells the PageNavigationThrottle to not throttle anything!
+  void AlwaysProceed();
+
+  // Resumes a deferred navigation request. Does nothing if a response isn't
+  // expected.
+  void Resume();
+
+  // Cancels a deferred navigation request. Does nothing if a response isn't
+  // expected.
+  void CancelDeferredNavigation(NavigationThrottle::ThrottleCheckResult result);
+
+ private:
+  int navigation_id_;
+  base::WeakPtr<page::PageHandler> page_handler_;
+  bool response_pending_;

[nasko, 2016/07/13 22:37:34]

nit: Some basic comments on these will be useful.

[alex clarke (OOO till 29th), 2016/07/14 16:06:04]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(PageNavigationThrottle);
+};
+
+}  // namespace devtools
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVTOOLS_PAGE_NAVIGATION_THROTTLE_H_