Guard Ash code with USE_ASH in chrome/browser/lifetime/

chrome/browser/lifetime/application_lifetime_aura.cc

Index: chrome/browser/lifetime/application_lifetime_aura.cc
diff --git a/chrome/browser/lifetime/application_lifetime_aura.cc b/chrome/browser/lifetime/application_lifetime_aura.cc
index 75d67bae8588d0be4b9bddcc62e7089cd362d412..a082d3a25aa328778024eb02ff8cfd34a7fb1c60 100644
--- a/chrome/browser/lifetime/application_lifetime_aura.cc
+++ b/chrome/browser/lifetime/application_lifetime_aura.cc
@@ -4,7 +4,6 @@
 
 #include "chrome/browser/lifetime/application_lifetime.h"
 
-#include "ash/shell.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/notifications/notification_ui_manager.h"
@@ -13,6 +12,10 @@
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/views/widget/widget.h"
 
+#if defined(USE_ASH)
+#include "ash/shell.h"
+#endif
+
 namespace chrome {
 
 void HandleAppExitingForPlatform() {
@@ -20,6 +23,7 @@ void HandleAppExitingForPlatform() {
   // and windows created by Ash (launcher, background, etc).
   g_browser_process->notification_ui_manager()->CancelAll();
 
+#if defined(USE_ASH)
   // This may be called before |ash::Shell| is initialized when
   // XIOError is reported.  crbug.com/150633.
   if (ash::Shell::HasInstance()) {
@@ -28,6 +32,7 @@ void HandleAppExitingForPlatform() {
     aura::client::GetCaptureClient(ash::Shell::GetPrimaryRootWindow())->
         SetCapture(NULL);
   }
+#endif  // defined(USE_ASH)
 
   views::Widget::CloseAllSecondaryWidgets();
 
@@ -43,7 +48,7 @@ void HandleAppExitingForPlatform() {
     // NotifyAndTerminate does nothing if called more than once.
     NotifyAndTerminate(true);
   }
-#endif  // OS_CHROMEOS
+#endif  // defined(OS_CHROMEOS)

[sky, 2015/11/20 23:46:40]

IMO this style of comments are a waste.

[mohsen, 2015/11/21 01:05:17]

Do you mean the whole comment or just the part I added? If the former, that
definitely makes sense in cases like here where the block is small.

[sky, 2015/11/22 16:00:22]

I mean the trailing // defined(OS_CHROMEOS). Comments like that are useful for
ifdefs spanning a large number of lines, or when there are lots of nested
ifdefs, but that isn't the case here. The style guide doesn't comment one way or
the other on this, so I leave the decision to you.

 }
 
 }  // namespace chrome