Reference written files relatively when possible.

tools/gn/ninja_build_writer.cc

Index: tools/gn/ninja_build_writer.cc
diff --git a/tools/gn/ninja_build_writer.cc b/tools/gn/ninja_build_writer.cc
index 12a37e13d8b5eaa735339b37a8ebed52b47fb670..a51b38bf5eaedc50a3c63bd41ead48354481496f 100644
--- a/tools/gn/ninja_build_writer.cc
+++ b/tools/gn/ninja_build_writer.cc
@@ -152,11 +152,19 @@ void NinjaBuildWriter::WriteNinjaRules() {
   // Other files read by the build.
   EscapeOptions path_escaping;
   path_escaping.mode = ESCAPE_NINJA_COMMAND;
+
   std::vector<SourceFile> written_files = g_scheduler->GetWrittenFiles();
-  for (const auto& written_file : written_files)
-    out_ << " " <<
-        EscapeString(FilePathToUTF8(build_settings_->GetFullPath(written_file)),
-                     path_escaping, nullptr);
+  for (const auto& written_file : written_files) {
+    Err err;
+    base::FilePath::StringType fileref = ComputeStringInOutputDir(

[brettw, 2015/07/31 23:36:55]

I think RebasePath in filesystem_utils.h will handle all cases of converting a
SourceFile string to be relative to a given directory. If not, we should fix it.

+        build_settings_->build_dir(), written_file, &err);
+    out_ << " ";
+    if (!err.has_error())
+      EscapeStringToStream(out_, FilePathToUTF8(fileref), path_escaping);
+    else
+      EscapeStringToStream(out_,
+          written_file.Resolve(build_settings_->root_path()), path_escaping);

[Peter Mayo, 2015/07/31 19:08:07]

Oops, forgot to change to UTF8.

+  }
 
   out_ << ": gn\n"
        << "  generator = 1\n"