[on-hold][subresource_filter] Add ActivationTracker to track all activated contents

chrome/browser/subresource_filter/subresource_filter_profile_context.h

Index: chrome/browser/subresource_filter/subresource_filter_profile_context.h
diff --git a/chrome/browser/subresource_filter/subresource_filter_profile_context.h b/chrome/browser/subresource_filter/subresource_filter_profile_context.h
index 582e041d7a13cf72d5fddf398a15577b81a60027..024e01c94c6d95af4021498621e70c9305795e51 100644
--- a/chrome/browser/subresource_filter/subresource_filter_profile_context.h
+++ b/chrome/browser/subresource_filter/subresource_filter_profile_context.h
@@ -11,6 +11,7 @@
 #include "components/keyed_service/core/keyed_service.h"
 
 class Profile;
+class SubresourceFilterActivationTracker;
 class SubresourceFilterContentSettingsManager;
 
 // This class holds profile scoped context for subresource filtering.
@@ -19,12 +20,17 @@ class SubresourceFilterProfileContext : public KeyedService {
   explicit SubresourceFilterProfileContext(Profile* profile);
   ~SubresourceFilterProfileContext() override;
 
+  SubresourceFilterActivationTracker* activation_tracker() const {
+    return activation_tracker_.get();
+  }
+
  private:
   // KeyedService:
   void Shutdown() override;
 
   std::unique_ptr<SubresourceFilterContentSettingsManager>
       content_settings_manager_;
+  std::unique_ptr<SubresourceFilterActivationTracker> activation_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(SubresourceFilterProfileContext);
 };