Change uses of base::JoinString to pass StringPieces where possible.

extensions/common/features/feature_provider.cc

 // Copyright 2013 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 "extensions/common/features/feature_provider.h"
 
 #include <map>
 #include <memory>
 
 #include "base/command_line.h"
@@ skipping 122 matching lines @@
     return iter->second.get();
   else
     return nullptr;
 }
 
 Feature* FeatureProvider::GetParent(Feature* feature) const {
   CHECK(feature);
   if (feature->no_parent())
     return nullptr;
 
-  std::vector<std::string> split = base::SplitString(
+  std::vector<base::StringPiece> split = base::SplitStringPiece(
       feature->name(), ".", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
   if (split.size() < 2)
     return nullptr;
   split.pop_back();
   return GetFeature(base::JoinString(split, "."));
 }
 
 // Children of a given API are named starting with parent.name()+".", which
 // means they'll be contiguous in the features_ std::map.
 std::vector<Feature*> FeatureProvider::GetChildren(
@@ skipping 22 matching lines @@
 void FeatureProvider::AddFeature(base::StringPiece name,
                                  std::unique_ptr<Feature> feature) {
   features_[name.as_string()] = std::move(feature);
 }
 
 void FeatureProvider::AddFeature(base::StringPiece name, Feature* feature) {
   features_[name.as_string()] = std::unique_ptr<Feature>(feature);
 }
 
 }  // namespace extensions