Implement rules removal for WebRequestRulesRegistry

chrome/browser/extensions/api/declarative/url_matcher.cc

Index: chrome/browser/extensions/api/declarative/url_matcher.cc
diff --git a/chrome/browser/extensions/api/declarative/url_matcher.cc b/chrome/browser/extensions/api/declarative/url_matcher.cc
index 91ee8b55c7ac3468def1e2b71ab4fdf938cd3d61..30993cd888ad9eb2979f995e6770f337c3b30fd5 100644
--- a/chrome/browser/extensions/api/declarative/url_matcher.cc
+++ b/chrome/browser/extensions/api/declarative/url_matcher.cc
@@ -344,6 +344,10 @@ void URLMatcherConditionFactory::ForgetUnusedPatterns(
   }
 }
 
+bool URLMatcherConditionFactory::IsEmpty() const {
+  return pattern_singletons_.empty();
+}
+
 URLMatcherCondition URLMatcherConditionFactory::CreateCondition(
     URLMatcherCondition::Criterion criterion,
     const std::string& pattern) {
@@ -480,6 +484,16 @@ std::set<URLMatcherConditionSet::ID> URLMatcher::MatchURL(const GURL& url) {
   return result;
 }
 
+bool URLMatcher::IsEmpty() const {
+  return condition_factory_.IsEmpty() &&
+      url_matcher_condition_sets_.empty() &&
+      substring_match_triggers_.empty() &&
+      full_url_matcher_.IsEmpty() &&
+      url_component_matcher_.IsEmpty() &&
+      registered_full_url_patterns_.empty() &&
+      registered_url_component_patterns_.empty();
+}
+
 void URLMatcher::UpdateSubstringSetMatcher(bool full_url_conditions) {
   // The purpose of |full_url_conditions| is just that we need to execute
   // the same logic once for Full URL searches and once for URL Component