Implement initial chrome.browserAction.openPopup API.

chrome/common/extensions/features/complex_feature.cc

Index: chrome/common/extensions/features/complex_feature.cc
diff --git a/chrome/common/extensions/features/complex_feature.cc b/chrome/common/extensions/features/complex_feature.cc
index 5b11019fcf63d27f0b7654d7da3342481c423824..a1cedfaacba76e4e0f5747180ee15629a13949a2 100644
--- a/chrome/common/extensions/features/complex_feature.cc
+++ b/chrome/common/extensions/features/complex_feature.cc
@@ -66,8 +66,8 @@ std::set<Feature::Context>* ComplexFeature::GetContexts() {
 }
 
 bool ComplexFeature::IsInternal() const {
-  NOTREACHED();
-  return false;
+  // TODO(justinlin): Same as the above TODO.
+  return features_[0]->IsInternal();
 }
 
 std::string ComplexFeature::GetAvailabilityMessage(AvailabilityResult result,