Fix GN command-line quoting on Windows.

BUG=
R=scottmg@chromium.org

Review URL: https://codereview.chromium.org/41263003

Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: ce7fea266dc81fb3fdaf207241772234de2ac4fd

tools/gn/ninja_build_writer.cc

diff --git a/tools/gn/ninja_build_writer.cc b/tools/gn/ninja_build_writer.cc
index a6d6485..b7cfdd7 100644
--- a/tools/gn/ninja_build_writer.cc
+++ b/tools/gn/ninja_build_writer.cc
@@ -51,6 +51,12 @@
 
   EscapeOptions escape_shell;
   escape_shell.mode = ESCAPE_SHELL;
+#if defined(OS_WIN)
+  // The command line code quoting varies by platform. We have one string,
+  // possibly with spaces, that we want to quote. The Windows command line
+  // quotes again, so we don't want quoting. The Posix one doesn't.
+  escape_shell.inhibit_quoting = true;
+#endif
 
   const CommandLine& our_cmdline = *CommandLine::ForCurrentProcess();
   const CommandLine::SwitchMap& switches = our_cmdline.GetSwitches();