Fixes for -Wunused-function on Linux, Android and ChromeOS

chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc

Index: chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
diff --git a/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc b/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
index b8b7d2f3dcac7ed62fa71028f696ac8f7d4d5fac..a3e764677bc3fc73f9a328466e58c6b58671ca72 100644
--- a/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
+++ b/chrome/browser/ui/aura/chrome_browser_main_extra_parts_aura.cc
@@ -28,6 +28,7 @@
 
 namespace {
 
+#if !defined(OS_CHROMEOS) && defined(USE_ASH)
 // Returns the desktop this process was initially launched in.
 chrome::HostDesktopType GetInitialDesktop() {
 #if defined(OS_WIN) && defined(USE_ASH)
@@ -39,6 +40,7 @@ chrome::HostDesktopType GetInitialDesktop() {
 #endif
   return chrome::HOST_DESKTOP_TYPE_NATIVE;
 }
+#endif  // !defined(OS_CHROMEOS) && defined(USE_ASH)
 
 }  // namespace