Do not activate system tray bubble by default

ash/mus/bridge/wm_shell_mus.cc

Index: ash/mus/bridge/wm_shell_mus.cc
diff --git a/ash/mus/bridge/wm_shell_mus.cc b/ash/mus/bridge/wm_shell_mus.cc
index 7c720a87d6ad8e634e968596c9a8b9bbe164bea0..49ce40242bc77862730488495437bfda1fdbe482 100644
--- a/ash/mus/bridge/wm_shell_mus.cc
+++ b/ash/mus/bridge/wm_shell_mus.cc
@@ -7,6 +7,7 @@
 #include <utility>
 
 #include "ash/common/accelerators/accelerator_controller.h"
+#include "ash/common/key_event_watcher.h"
 #include "ash/common/session/session_state_delegate.h"
 #include "ash/common/shell_delegate.h"
 #include "ash/common/shell_observer.h"
@@ -364,6 +365,10 @@ WmShellMus::CreateImmersiveFullscreenController() {
   return base::MakeUnique<ImmersiveFullscreenController>();
 }
 
+std::unique_ptr<KeyEventWatcher> WmShellMus::CreateKeyEventWatcher() {
+  return std::unique_ptr<KeyEventWatcher>();

[James Cook, 2016/09/22 21:17:17]

Please file a bug to implement this for mus, reference the bug here, and add a
NOTIMPLEMENTED(), like the other Create() functions above.

[oshima, 2016/09/23 09:37:20]

Done.

FYI: ImmersiveFullscreenController doesn't have it.

[James Cook, 2016/09/23 16:32:28]

ImmersiveFullscreenController lives in //ash/shared, which means it has been
ported to mustash.

[oshima, 2016/09/23 19:19:53]

Sorry I misread the code.

+}
+
 void WmShellMus::OnOverviewModeStarting() {
   FOR_EACH_OBSERVER(ShellObserver, *shell_observers(),
                     OnOverviewModeStarting());