tools/gn: Convert for loops to use the new range-based loops in C++11.

tools/gn/ninja_target_writer.cc

 // 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.
 
 #include "tools/gn/ninja_target_writer.h"
 
 #include <fstream>
 #include <sstream>
 
 #include "base/files/file_util.h"
@@ skipping 177 matching lines @@
        << GetNinjaRulePrefixForToolchain(settings_)
        << Toolchain::ToolTypeToName(Toolchain::TYPE_STAMP);
 
   // Script file (if applicable).
   if (add_script_source_as_dep) {
     out_ << " ";
     path_output_.WriteFile(out_, target_->action_values().script());
   }
 
   // Input files are order-only deps.
-  const Target::FileList& prereqs = target_->inputs();
-  for (size_t i = 0; i < prereqs.size(); i++) {
+  for (const auto& input : target_->inputs()) {
     out_ << " ";
-    path_output_.WriteFile(out_, prereqs[i]);
+    path_output_.WriteFile(out_, input);
   }
   if (list_sources_as_input_deps) {
-    const Target::FileList& sources = target_->sources();
-    for (size_t i = 0; i < sources.size(); i++) {
+    for (const auto& source : target_->sources()) {
       out_ << " ";
-      path_output_.WriteFile(out_, sources[i]);
+      path_output_.WriteFile(out_, source);
     }
   }
 
   // The different souces of input deps may duplicate some targets, so uniquify
   // them (ordering doesn't matter for this case).
   std::set<const Target*> unique_deps;
 
   // Hard dependencies that are direct or indirect dependencies.
   const std::set<const Target*>& hard_deps = target_->recursive_hard_deps();
   for (const auto& dep : hard_deps)
     unique_deps.insert(dep);
 
   // Extra hard dependencies passed in.
   unique_deps.insert(extra_hard_deps.begin(), extra_hard_deps.end());
 
   // Toolchain dependencies. These must be resolved before doing anything.
   // This just writs all toolchain deps for simplicity. If we find that
   // toolchains often have more than one dependency, we could consider writing
   // a toolchain-specific stamp file and only include the stamp here.
   const LabelTargetVector& toolchain_deps = target_->toolchain()->deps();
-  for (size_t i = 0; i < toolchain_deps.size(); i++)
-    unique_deps.insert(toolchain_deps[i].ptr);
+  for (const auto& toolchain_dep : toolchain_deps)
+    unique_deps.insert(toolchain_dep.ptr);
 
   for (const auto& dep : unique_deps) {
     DCHECK(!dep->dependency_output_file().value().empty());
     out_ << " ";
     path_output_.WriteFile(out_, dep->dependency_output_file());
   }
 
   out_ << "\n";
   return input_stamp_file;
 }
@@ skipping 16 matching lines @@
        << GetNinjaRulePrefixForToolchain(settings_)
        << Toolchain::ToolTypeToName(Toolchain::TYPE_STAMP);
   path_output_.WriteFiles(out_, files);
 
   if (!order_only_deps.empty()) {
     out_ << " ||";
     path_output_.WriteFiles(out_, order_only_deps);
   }
   out_ << std::endl;
 }