Extensions: Only create Web request rules registry if Declarative Web Request is enabled.

extensions/common/features/complex_feature.cc

Index: extensions/common/features/complex_feature.cc
diff --git a/extensions/common/features/complex_feature.cc b/extensions/common/features/complex_feature.cc
index ed129da1e6413884c70e853bcb3b27c4aa4ed90b..35680d17831dd30db7671ccd34138c64ea03a7b8 100644
--- a/extensions/common/features/complex_feature.cc
+++ b/extensions/common/features/complex_feature.cc
@@ -98,6 +98,24 @@ bool ComplexFeature::IsIdInWhitelist(const std::string& extension_id) const {
   return false;
 }
 
+Feature::Availability ComplexFeature::IsAvailableToChannel(
+    version_info::Channel channel) const {
+  Feature::Availability first_availability =
+      features_[0]->IsAvailableToChannel(channel);
+  if (first_availability.is_available())
+    return first_availability;
+
+  for (FeatureList::const_iterator it = features_.begin() + 1;
+       it != features_.end(); ++it) {
+    Availability availability = (*it)->IsAvailableToChannel(channel);
+    if (availability.is_available())
+      return availability;
+  }
+  // If none of the SimpleFeatures are available, we return the availability
+  // info of the first SimpleFeature that was not available.
+  return first_availability;
+}
+
 bool ComplexFeature::IsInternal() const {
   // Constructor verifies that composed features are consistent, thus we can
   // return just the first feature's value.