Make sky/tools/packager build on Mac

sky/tools/packager/loader.cc

 // Copyright 2015 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 "sky/tools/packager/loader.h"
 
-#include <utility>
-
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/logging.h"
 #include "base/strings/string_util.h"
 #include "sky/tools/packager/logging.h"
 #include "sky/tools/packager/scope.h"
 #include "sky/tools/packager/switches.h"
 
 namespace {
@@ skipping 18 matching lines @@
     if (component == base::FilePath::kParentDirectory)
       result = result.DirName();
     else
       result = result.Append(component);
   }
   return result;
 }
 
 class Loader {
  public:
-  Loader(base::FilePath package_root);
+  Loader(const base::FilePath& package_root);
 
   std::string CanonicalizePackageURL(std::string url);
   Dart_Handle CanonicalizeURL(Dart_Handle library, Dart_Handle url);
   Dart_Handle Import(Dart_Handle url);
   Dart_Handle Source(Dart_Handle library, Dart_Handle url);
 
  private:
   base::FilePath package_root_;
 
   DISALLOW_COPY_AND_ASSIGN(Loader);
 };
 
-Loader::Loader(base::FilePath package_root)
-    : package_root_(std::move(package_root)) {
+Loader::Loader(const base::FilePath& package_root)
+    : package_root_(package_root) {
 }
 
 std::string Loader::CanonicalizePackageURL(std::string url) {
   DCHECK(StartsWithASCII(url, "package:", true));
   ReplaceFirstSubstringAfterOffset(&url, 0, "package:", "");
   return package_root_.Append(url).AsUTF8Unsafe();
 }
 
 Dart_Handle Loader::CanonicalizeURL(Dart_Handle library, Dart_Handle url) {
   std::string string = StringFromDart(url);
   if (StartsWithASCII(string, "dart:", true))
     return url;
   if (StartsWithASCII(string, "package:", true))
-    return StringToDart(CanonicalizePackageURL(std::move(string)));
+    return StringToDart(CanonicalizePackageURL(string));
   base::FilePath base_path(StringFromDart(Dart_LibraryUrl(library)));
   base::FilePath resolved_path = base_path.DirName().Append(string);
   base::FilePath normalized_path = SimplifyPath(resolved_path);
   return StringToDart(normalized_path.AsUTF8Unsafe());
 }
 
 Dart_Handle Loader::Import(Dart_Handle url) {
   Dart_Handle source = StringToDart(Fetch(StringFromDart(url)));
   Dart_Handle result = Dart_LoadLibrary(url, source, 0, 0);
   LogIfError(result);
@@ skipping 39 matching lines @@
 }
 
 void LoadSkyInternals() {
   DartApiScope api_scope;
 
   Dart_Handle library_name = StringToDart(kSkyInternalsLibraryName);
   std::string url = GetLoader().CanonicalizePackageURL(kSkyInternalsURL);
   LogIfError(Dart_LoadLibrary(library_name, StringToDart(Fetch(url)), 0, 0));
 }
 
-void LoadScript(std::string url) {
+void LoadScript(const std::string& url) {
   LogIfError(
       Dart_LoadScript(StringToDart(url), StringToDart(Fetch(url)), 0, 0));
 }