Restructure the events target into two components:

ui/events/keycodes/keyboard_code_conversion_gtk.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /*
  * Copyright (C) 2006, 2007 Apple Inc.  All rights reserved.
  * Copyright (C) 2006 Michael Emmel mike.emmel@gmail.com
  * Copyright (C) 2007 Holger Hans Peter Freyther
  * Copyright (C) 2008 Collabora, Ltd.  All rights reserved.
  * Copyright (C) 2008, 2009 Google Inc.
@@ skipping 18 matching lines @@
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // WindowsKeyCodeForGdkKeyCode is copied from platform/gtk/KeyEventGtk.cpp
 
 #ifndef UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_GTK_H_
 #define UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_GTK_H_
 
-#include "ui/events/events_export.h"
+#include "ui/events/events_base_export.h"
 #include "ui/events/keycodes/keyboard_codes_posix.h"
 
 typedef struct _GdkEventKey GdkEventKey;
 
 namespace ui {
 
-EVENTS_EXPORT KeyboardCode WindowsKeyCodeForGdkKeyCode(int keycode);
+EVENTS_BASE_EXPORT KeyboardCode WindowsKeyCodeForGdkKeyCode(int keycode);
 
-EVENTS_EXPORT int GdkKeyCodeForWindowsKeyCode(KeyboardCode keycode, bool shift);
+EVENTS_BASE_EXPORT int GdkKeyCodeForWindowsKeyCode(KeyboardCode keycode,
+                                                   bool shift);
 
 // For WebKit DRT testing: simulate the native keycode for the given
 // input |keycode|.  Return the native keycode.
-EVENTS_EXPORT int GdkNativeKeyCodeForWindowsKeyCode(KeyboardCode keycode,
-                                                bool shift);
+EVENTS_BASE_EXPORT int GdkNativeKeyCodeForWindowsKeyCode(KeyboardCode keycode,
+                                                         bool shift);
 
 } // namespace ui
 
 #endif  // UI_EVENTS_KEYCODES_KEYBOARD_CODE_CONVERSION_GTK_H_