Change the logic how Subesource Filter propagates activation.

components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h

Index: components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h
diff --git a/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h b/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h
index 2c9b4d43ff028fef7046d187a6785fe3786b0246..4b1cc04a8e13258c3e93ec95f6e2f8ccfea3d003 100644
--- a/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h
+++ b/components/subresource_filter/content/browser/content_subresource_filter_driver_factory.h
@@ -56,18 +56,13 @@ class ContentSubresourceFilterDriverFactory
   bool IsWhitelisted(const GURL& url) const;
   bool IsBlacklisted(const GURL& url) const;
 
-  // Returns true if the subresource filtering should be active for the |url|.
-  bool ShouldActivateForURL(const GURL& url) const;
-
-  // Adds the host of the |url| to the set of hosts for which Subresource
-  // Filtering should be active for the lifetime of this WebContents.
-  void AddHostOfURLToActivationSet(const GURL& url);
-
   // Whitelists the host of |url|, so that page loads with the main-frame
   // document being loaded from this host will be exempted from subresource
   // filtering for the lifetime of this WebContents.
   void AddHostOfURLToWhitelistSet(const GURL& url);
 
+  void AddToActivationHitsSet(const GURL& url);
+
   // Called when Safe Browsing detects that the |url| corresponding to the load
   // of the main frame belongs to the blacklist with |threat_type|. If the
   // blacklist is the Safe Browsing Social Engineering ads landing, then |url|
@@ -96,7 +91,7 @@ class ContentSubresourceFilterDriverFactory
       content::RenderFrameHost* render_frame_host,
       const GURL& url);
 
-  const HostSet& activation_set() const { return activate_on_hosts_; }
+  const HostSet& hits_set() const { return hits_hosts_; }
   const HostSet& whitelisted_set() const { return whitelisted_hosts_; }
   ActivationState activation_state() { return activation_state_; }
 
@@ -136,14 +131,21 @@ class ContentSubresourceFilterDriverFactory
 
   void set_activation_state(const ActivationState& new_activation_state);
 
+  bool IsHit(const GURL& url) const;
+
   static const char kWebContentsUserDataKey[];
 
   FrameHostToOwnedDriverMap frame_drivers_;
   std::unique_ptr<SubresourceFilterClient> client_;
 
-  HostSet activate_on_hosts_;
   HostSet whitelisted_hosts_;
 
+  // List of host+path of the URLs, where the Safe Browsing detected hit

[engedy, 2016/10/12 09:32:29]

nit: Extra words in this sentence.

[melandory, 2016/10/12 12:29:00]

Haven't found them, but changed the formulation, so might accidentally fixed the
issue.

[engedy, 2016/10/12 12:47:05]

Phrasing suggestion:

During the course of one navigation, collects those URLs in the redirect chain
that match Safe Browsing blacklists. The URLs stripped to (host + path). When
the navigation is committed, the activation signal is sent depending on whether
the (host + path) of the final URL is in this list. Contents are wiped between
navigations.

+  // to the list of interest. When the navigation is commited this list is used
+  // to determine whenever the activation signal should be send, then all

[engedy, 2016/10/12 09:32:29]

nit: s/send/sent/ 

[melandory, 2016/10/12 12:29:00]

Done.

+  // entities is deleted from the list.

[engedy, 2016/10/12 09:32:29]

nit: s/is/are/

[melandory, 2016/10/12 12:29:00]

Done.

+  HostSet hits_hosts_;

[engedy, 2016/10/12 09:32:29]

This set no longer stores hosts, but host+path pairs. Let's reflect that in the
type name.

Also, how about naming this something like |safe_browsing_blacklisted_patterns|,
so it's more expressive? I would also suggest renaming helper functions
similarly.

[melandory, 2016/10/12 12:29:00]

Done.

[engedy, 2016/10/12 12:47:05]

Please see the two other requests in this comment too.

+
   ActivationState activation_state_;
 
   DISALLOW_COPY_AND_ASSIGN(ContentSubresourceFilterDriverFactory);