Introduce the ThrottleManager

components/subresource_filter/content/browser/activation_state_computing_navigation_throttle.h

 // Copyright 2017 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 COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_FRAME_ACTIVATION_NAVIGATION_THROTTLE_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_FRAME_ACTIVATION_NAVIGATION_THROTTLE_H_
 
 #include <memory>
 
 #include "base/macros.h"
@@ skipping 22 matching lines @@
   // has been established that activation computation is needed.
   static std::unique_ptr<ActivationStateComputingNavigationThrottle>
   CreateForMainFrame(content::NavigationHandle* navigation_handle);
 
   // It is illegal to create an activation computing throttle for subframes
   // whose parents are not activated. Similarly, |ruleset_handle| should be
   // non-null.
   static std::unique_ptr<ActivationStateComputingNavigationThrottle>
   CreateForSubframe(content::NavigationHandle* navigation_handle,
                     VerifiedRuleset::Handle* ruleset_handle,
-                    const ActivationState& parent_activation_state);
+                    const ActivationState& parent_activation_state,
+                    base::OnceClosure first_disallowed_load_callback);

[engedy, 2017/03/10 17:36:20]

optional nit: On second read, it seems a bit weird to plumb this through here,
considering that this throttle is not doing any filtering. Especially given the
two different code paths for main/subframes here and in the caller.

Maybe we could let the ThrottleManager set it on the ADSF post-construction?

[Charlie Harrison, 2017/03/14 23:18:31]

Sure. I added a setter on the ADSF.

 
   ~ActivationStateComputingNavigationThrottle() override;
 
   // Notification for main frames when the page level activation is computed.
   // Must be called at most once before WillProcessResponse is called on this
   // throttle. If it is never called, or it is called with a DISABLED state,
   // this object will never delay the navigation.
   void NotifyPageActivationWithRuleset(
       VerifiedRuleset::Handle* ruleset_handle,
-      const ActivationState& page_activation_state);
+      const ActivationState& page_activation_state,
+      base::OnceClosure first_disallowed_load_callback);
 
   // content::NavigationThrottle:
   content::NavigationThrottle::ThrottleCheckResult WillProcessResponse()
       override;
 
   // After the navigation is finished, the client may optionally choose to
   // continue using the DocumentSubresourceFilter that was used to compute the
   // activation state for this frame. The transfered filter can be cached and
   // used to calculate load policy for subframe navigations occuring in this
   // frame.
   std::unique_ptr<AsyncDocumentSubresourceFilter> ReleaseFilter();
 
   // Gets the activation state calculated for this navigation. Must be called
   // after the navigation is resumed from getting paused in WillProcessResponse,
   // which, for example, will have happened at ReadyToCommitNavigation.
   const ActivationState& GetActivationState() const;

[engedy, 2017/03/10 17:36:20]

Now that the ADSF has the state, do we need this and the corresponding member
variable anymore?

[Charlie Harrison, 2017/03/14 23:18:31]

Nope, removed.

 
  private:
   void SetActivationStateAndResume(ActivationState state);
 
   ActivationStateComputingNavigationThrottle(
       content::NavigationHandle* navigation_handle,
       const base::Optional<ActivationState> parent_activation_state,
-      VerifiedRuleset::Handle* ruleset_handle);
+      VerifiedRuleset::Handle* ruleset_handle,
+      base::OnceClosure first_disallowed_load_callback);
 
   // These members are optional to allow DCHECKing their existence at certain
   // points in the navigation flow.
   base::Optional<ActivationState> activation_state_;
   base::Optional<ActivationState> parent_activation_state_;
 
   std::unique_ptr<AsyncDocumentSubresourceFilter> async_filter_;
 
   // Must outlive this class. For main frame navigations, this member will be
   // nullptr until NotifyPageActivationWithRuleset is called.
   VerifiedRuleset::Handle* ruleset_handle_;
 
+  base::OnceClosure first_disallowed_load_callback_;
+
   base::WeakPtrFactory<ActivationStateComputingNavigationThrottle>
       weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ActivationStateComputingNavigationThrottle);
 };
 
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CONTENT_BROWSER_FRAME_ACTIVATION_NAVIGATION_THROTTLE_H_