Enable building headless_shell in MAC. This is an initial implementation with a hidden window, rath…

headless/lib/browser/headless_content_browser_client.cc

Index: headless/lib/browser/headless_content_browser_client.cc
diff --git a/headless/lib/browser/headless_content_browser_client.cc b/headless/lib/browser/headless_content_browser_client.cc
index e993fc18df2a04a9a3002d92a841ad4e85440948..ade0c60f0ba2b403e4d39ab1236135b68086da06 100644
--- a/headless/lib/browser/headless_content_browser_client.cc
+++ b/headless/lib/browser/headless_content_browser_client.cc
@@ -170,6 +170,7 @@ void HeadlessContentBrowserClient::GetQuotaSettings(
       callback);
 }
 
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
 void HeadlessContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     const base::CommandLine& command_line,
     int child_process_id,
@@ -180,6 +181,7 @@ void HeadlessContentBrowserClient::GetAdditionalMappedFilesForChildProcess(
     mappings->Share(kCrashDumpSignal, crash_signal_fd);
 #endif  // defined(HEADLESS_USE_BREAKPAD)
 }
+#endif  // defined(OS_POSIX) && !defined(OS_MACOSX)
 
 void HeadlessContentBrowserClient::AppendExtraCommandLineSwitches(
     base::CommandLine* command_line,