Adding Navigation Throttles to DevTools

content/browser/devtools/page_navigation_throttle.h

Index: content/browser/devtools/page_navigation_throttle.h
diff --git a/content/browser/devtools/page_navigation_throttle.h b/content/browser/devtools/page_navigation_throttle.h
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+// 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:
+  // An opaque ID assigned by the PageHandler, used to allow the protocol client
+  // to refer to this navigation throttle.
+  const int navigation_id_;
+
+  // The PageHandler that this navigation throttle is associated with.
+  base::WeakPtr<page::PageHandler> page_handler_;
+
+  // Whether or not a navigation was deferred. If deferred we expect a
+  // subsequent call to AlwaysProceed, Resume or CancelDeferredNavigation.
+  bool navigation_deferred_;
+
+  DISALLOW_COPY_AND_ASSIGN(PageNavigationThrottle);
+};
+
+}  // namespace devtools
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVTOOLS_PAGE_NAVIGATION_THROTTLE_H_