Restructure the events target into two components:

ui/events/keycodes/keyboard_code_conversion_mac.h

Index: ui/events/keycodes/keyboard_code_conversion_mac.h
diff --git a/ui/events/keycodes/keyboard_code_conversion_mac.h b/ui/events/keycodes/keyboard_code_conversion_mac.h
index d7c05b0072cab3d2ff925b4fc5c09ed1cd10f4e4..d74c57948b45b5fa5b23e1112aed6805553edc95 100644
--- a/ui/events/keycodes/keyboard_code_conversion_mac.h
+++ b/ui/events/keycodes/keyboard_code_conversion_mac.h
@@ -8,7 +8,7 @@
 #import <Cocoa/Cocoa.h>
 
 #include "base/basictypes.h"
-#include "ui/events/events_export.h"
+#include "ui/events/events_base_export.h"
 #include "ui/events/keycodes/keyboard_codes_posix.h"
 
 namespace ui {
@@ -25,16 +25,17 @@ namespace ui {
 // -1 will be returned if the keycode can't be converted.
 // This function is mainly for simulating keyboard events in unit tests.
 // See |KeyboardCodeFromNSEvent| for reverse conversion.
-EVENTS_EXPORT int MacKeyCodeForWindowsKeyCode(KeyboardCode keycode,
-                                          NSUInteger flags,
-                                          unichar* character,
-                                          unichar* characterIgnoringModifiers);
+EVENTS_BASE_EXPORT int MacKeyCodeForWindowsKeyCode(
+    KeyboardCode keycode,
+    NSUInteger flags,
+    unichar* character,
+    unichar* characterIgnoringModifiers);
 
 // This implementation cribbed from:
 //   third_party/WebKit/Source/web/mac/WebInputEventFactory.mm
 // Converts |event| into a |KeyboardCode|.  The mapping is not direct as the Mac
 // has a different notion of key codes.
-EVENTS_EXPORT KeyboardCode KeyboardCodeFromNSEvent(NSEvent* event);
+EVENTS_BASE_EXPORT KeyboardCode KeyboardCodeFromNSEvent(NSEvent* event);
 
 } // namespace ui