Include "public" source files in generated Xcode project.

tools/gn/xcode_writer.cc

 // Copyright 2016 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/xcode_writer.h"
 
 #include <iomanip>
 #include <map>
 #include <memory>
 #include <sstream>
@@ skipping 386 matching lines @@
     const std::string& source_path,
     const std::string& config_name,
     const std::string& root_target,
     const std::string& ninja_extra_args,
     const BuildSettings* build_settings,
     TargetOsType target_os) {
   std::unique_ptr<PBXProject> main_project(
       new PBXProject("products", config_name, source_path, attributes));
   SourceDir source_dir("//");
 
-  // Add all source files for indexing.
+  // Add all source files for indexing, both private and public.
   std::vector<SourceFile> sources;
   for (const Target* target : all_targets) {
     for (const SourceFile& source : target->sources()) {
       if (IsStringInOutputDir(build_settings->build_dir(), source.value()))
         continue;
 
       sources.push_back(source);
     }
+
+    if (target->all_headers_public())
+      continue;
+
+    for (const SourceFile& source : target->public_headers()) {
+      if (IsStringInOutputDir(build_settings->build_dir(), source.value()))
+        continue;
+
+      sources.push_back(source);
+    }
   }
 
   // Sort sources to ensure determinisn of the project file generation and
   // remove duplicate reference to the source files (can happen due to the
   // bundle_data targets).
   std::sort(sources.begin(), sources.end());
   sources.erase(std::unique(sources.begin(), sources.end()), sources.end());
 
   for (const SourceFile& source : sources) {
     std::string source_file = RebasePath(source.value(), source_dir,
@@ skipping 170 matching lines @@
     for (auto* object : pair.second) {
       object->Print(out, 2);
     }
     out << "/* End " << ToString(pair.first) << " section */\n";
   }
 
   out << "\t};\n"
       << "\trootObject = " << project->Reference() << ";\n"
       << "}\n";
 }