Use simplify operator< implementations in tools/

tools/gn/label.h

 // Copyright (c) 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.
 
 #ifndef TOOLS_GN_LABEL_H_
 #define TOOLS_GN_LABEL_H_
 
 #include "base/containers/hash_tables.h"
 #include "tools/gn/source_dir.h"
 
@@ skipping 53 matching lines @@
 
   bool operator==(const Label& other) const {
     return name_ == other.name_ && dir_ == other.dir_ &&
            toolchain_dir_ == other.toolchain_dir_ &&
            toolchain_name_ == other.toolchain_name_;
   }
   bool operator!=(const Label& other) const {
     return !operator==(other);
   }
   bool operator<(const Label& other) const {
-    // TODO(brettw) could be optimized to avoid an extra full string check
-    // (one for operator==, one for <).
-    if (dir_ != other.dir_)
-      return dir_ < other.dir_;
-    if (name_ != other.name_)
-      return name_ < other.name_;
-    if (toolchain_dir_ != other.toolchain_dir_)
-      return toolchain_dir_ < other.toolchain_dir_;
+    if (int c = dir_.value().compare(other.dir_.value()))
+      return c < 0;
+    if (int c = name_.compare(other.name_))
+      return c < 0;
+    if (int c = toolchain_dir_.value().compare(other.toolchain_dir_.value()))
+      return c < 0;
     return toolchain_name_ < other.toolchain_name_;
   }
 
   void swap(Label& other) {
     dir_.swap(other.dir_);
     name_.swap(other.name_);
     toolchain_dir_.swap(other.toolchain_dir_);
     toolchain_name_.swap(other.toolchain_name_);
   }
 
@@ skipping 24 matching lines @@
   }
 };
 
 }  // namespace BASE_HASH_NAMESPACE
 
 inline void swap(Label& lhs, Label& rhs) {
   lhs.swap(rhs);
 }
 
 #endif  // TOOLS_GN_LABEL_H_