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

components/subresource_filter/core/common/document_subresource_filter.cc

 // 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.
 
 #include "components/subresource_filter/core/common/document_subresource_filter.h"
 
 #include <utility>
 
 #include "base/logging.h"
 #include "base/trace_event/trace_event.h"
@@ skipping 33 matching lines @@
                  proto::ACTIVATION_TYPE_GENERICBLOCK)) {
     activation_state.generic_blocking_rules_disabled = true;
   }
   return activation_state;
 }
 
 DocumentSubresourceFilter::DocumentSubresourceFilter(
     url::Origin document_origin,
     ActivationState activation_state,
     scoped_refptr<const MemoryMappedRuleset> ruleset)
+    : DocumentSubresourceFilter(document_origin,
+                                activation_state,
+                                ruleset,
+                                nullptr) {}
+
+DocumentSubresourceFilter::DocumentSubresourceFilter(
+    url::Origin document_origin,
+    ActivationState activation_state,
+    scoped_refptr<const MemoryMappedRuleset> ruleset,
+    std::unique_ptr<RuleRecorder> recorder)
     : activation_state_(activation_state),
       ruleset_(std::move(ruleset)),
-      ruleset_matcher_(ruleset_->data(), ruleset_->length()) {
+      ruleset_matcher_(ruleset_->data(),
+                       ruleset_->length(),
+                       std::move(recorder)) {
   DCHECK_NE(activation_state_.activation_level, ActivationLevel::DISABLED);
   if (!activation_state_.filtering_disabled_for_document)
     document_origin_.reset(new FirstPartyOrigin(std::move(document_origin)));
 }
 
 DocumentSubresourceFilter::~DocumentSubresourceFilter() = default;
 
 LoadPolicy DocumentSubresourceFilter::GetLoadPolicy(
     const GURL& subresource_url,
     proto::ElementType subresource_type) {
@@ skipping 32 matching lines @@
       ++statistics_.num_loads_disallowed;
       return LoadPolicy::DISALLOW;
     } else if (activation_state_.activation_level == ActivationLevel::DRYRUN) {
       return LoadPolicy::WOULD_DISALLOW;
     }
   }
   return LoadPolicy::ALLOW;
 }
 
 }  // namespace subresource_filter