Add instrumentation hooks to mesaure which subresource filter rules are used.

components/subresource_filter/core/common/document_subresource_filter.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 COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_DOCUMENT_SUBRESOURCE_FILTER_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_DOCUMENT_SUBRESOURCE_FILTER_H_
 
 #include <stddef.h>
 
 #include <memory>
@@ skipping 39 matching lines @@
  public:
   // Constructs a new filter that will:
   //  -- Operate in a manner prescribed in |activation_state|.
   //  -- Filter subresource loads in the scope of a document loaded from
   //     |document_origin|.
   //  -- Hold a reference to and use |ruleset| for its entire lifetime.
   DocumentSubresourceFilter(url::Origin document_origin,
                             ActivationState activation_state,
                             scoped_refptr<const MemoryMappedRuleset> ruleset);
 
+  // Constructs a new filter that will:
+  //  -- Operate in a manner prescribed in |activation_state|.
+  //  -- Filter subresource loads in the scope of a document loaded from
+  //     |document_origin|.
+  //  -- Hold a reference to and use |ruleset| for its entire lifetime.
+  DocumentSubresourceFilter(url::Origin document_origin,
+                            ActivationState activation_state,
+                            scoped_refptr<const MemoryMappedRuleset> ruleset,
+                            std::unique_ptr<RuleRecorder> recorder);
+
   ~DocumentSubresourceFilter();
 
   ActivationState activation_state() const { return activation_state_; }
   const DocumentLoadStatistics& statistics() const { return statistics_; }
 
   // WARNING: This is only to allow DocumentSubresourceFilter's wrappers to
   // modify the |statistics|.
   // TODO(pkalinnikov): Find a better way to achieve this.
   DocumentLoadStatistics& statistics() { return statistics_; }
 
   LoadPolicy GetLoadPolicy(const GURL& subresource_url,
                            proto::ElementType subresource_type);
 
  private:
   const ActivationState activation_state_;
   const scoped_refptr<const MemoryMappedRuleset> ruleset_;
   const IndexedRulesetMatcher ruleset_matcher_;
 
   // Equals nullptr iff |activation_state_.filtering_disabled_for_document|.
   std::unique_ptr<FirstPartyOrigin> document_origin_;
 
   DocumentLoadStatistics statistics_;
 
   DISALLOW_COPY_AND_ASSIGN(DocumentSubresourceFilter);
 };
 
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CORE_COMMON_DOCUMENT_SUBRESOURCE_FILTER_H_