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

components/subresource_filter/core/common/indexed_ruleset.cc

Index: components/subresource_filter/core/common/indexed_ruleset.cc
diff --git a/components/subresource_filter/core/common/indexed_ruleset.cc b/components/subresource_filter/core/common/indexed_ruleset.cc
index edbbee88c9d1283af1ac0e1bf198c0d279d39ebc..5f991dc80ea8aa3f72ab6a99586e6564faa1f057 100644
--- a/components/subresource_filter/core/common/indexed_ruleset.cc
+++ b/components/subresource_filter/core/common/indexed_ruleset.cc
@@ -1,3 +1,4 @@
+
 // 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.
@@ -61,10 +62,17 @@ bool IndexedRulesetMatcher::Verify(const uint8_t* buffer, size_t size) {
 }
 
 IndexedRulesetMatcher::IndexedRulesetMatcher(const uint8_t* buffer, size_t size)
+    : IndexedRulesetMatcher(buffer, size, nullptr) {}
+
+IndexedRulesetMatcher::IndexedRulesetMatcher(
+    const uint8_t* buffer,
+    size_t size,
+    std::unique_ptr<RuleRecorder> recorder)
     : root_(flat::GetIndexedRuleset(buffer)),
       blacklist_(root_->blacklist_index()),
       whitelist_(root_->whitelist_index()),
-      deactivation_(root_->deactivation_index()) {}
+      deactivation_(root_->deactivation_index()),
+      recorder_(std::move(recorder)) {}
 
 bool IndexedRulesetMatcher::ShouldDisableFilteringForDocument(
     const GURL& document_url,
@@ -74,7 +82,7 @@ bool IndexedRulesetMatcher::ShouldDisableFilteringForDocument(
       document_url, parent_document_origin, proto::ELEMENT_TYPE_UNSPECIFIED,
       activation_type,
       FirstPartyOrigin::IsThirdParty(document_url, parent_document_origin),
-      false);
+      false, nullptr);
 }
 
 bool IndexedRulesetMatcher::ShouldDisallowResourceLoad(
@@ -85,10 +93,12 @@ bool IndexedRulesetMatcher::ShouldDisallowResourceLoad(
   const bool is_third_party = first_party.IsThirdParty(url);
   return !!blacklist_.FindMatch(url, first_party.origin(), element_type,
                                 proto::ACTIVATION_TYPE_UNSPECIFIED,
-                                is_third_party, disable_generic_rules) &&
+                                is_third_party, disable_generic_rules,
+                                recorder_.get()) &&
          !whitelist_.FindMatch(url, first_party.origin(), element_type,
                                proto::ACTIVATION_TYPE_UNSPECIFIED,
-                               is_third_party, disable_generic_rules);
+                               is_third_party, disable_generic_rules,
+                               recorder_.get());
 }
 
 }  // namespace subresource_filter