Rename wm_core_export.h to wm_export.h and the wm_core target to just wm

ui/wm/core/user_activity_detector.h

Index: ui/wm/core/user_activity_detector.h
diff --git a/ui/wm/core/user_activity_detector.h b/ui/wm/core/user_activity_detector.h
index 6a94db146c239f4e3a534cc42956b631bd0bf972..851f07ac325d7323791f3564ed8622c41260ca0a 100644
--- a/ui/wm/core/user_activity_detector.h
+++ b/ui/wm/core/user_activity_detector.h
@@ -10,14 +10,14 @@
 #include "base/observer_list.h"
 #include "base/time/time.h"
 #include "ui/events/event_handler.h"
-#include "ui/wm/core/wm_core_export.h"
+#include "ui/wm/wm_export.h"
 
 namespace wm {
 
 class UserActivityObserver;
 
 // Watches for input events and notifies observers that the user is active.
-class WM_CORE_EXPORT UserActivityDetector : public ui::EventHandler {
+class WM_EXPORT UserActivityDetector : public ui::EventHandler {
  public:
   // Minimum amount of time between notifications to observers.
   static const int kNotifyIntervalMs;