Restructure the events target into two components:

ui/ui_unittests.gyp

Index: ui/ui_unittests.gyp
diff --git a/ui/ui_unittests.gyp b/ui/ui_unittests.gyp
index 77ef4135741341fbcecfd3c63db2e3d71c24083b..bc7c5864a72c9b77edfec119ae0d4a557e716ec8 100644
--- a/ui/ui_unittests.gyp
+++ b/ui/ui_unittests.gyp
@@ -13,7 +13,6 @@
         '../base/base.gyp:base',
         '../skia/skia.gyp:skia',
         '../testing/gtest.gyp:gtest',
-        'events/events.gyp:events',
         'gfx/gfx.gyp:gfx',
       ],
       'sources': [
@@ -89,7 +88,7 @@
         '../third_party/libpng/libpng.gyp:libpng',
         '../url/url.gyp:url_lib',
         'base/strings/ui_strings.gyp:ui_strings',
-        'events/events.gyp:events',
+        'events/events.gyp:events_base',
         'run_ui_unittests',
         'shell_dialogs/shell_dialogs.gyp:shell_dialogs',
         'ui.gyp:keycode_converter',
@@ -155,7 +154,6 @@
         'base/cocoa/controls/blue_label_button_unittest.mm',
         'base/cocoa/controls/hover_image_menu_button_unittest.mm',
         'base/cocoa/controls/hyperlink_button_cell_unittest.mm',
-        'base/cocoa/events_mac_unittest.mm',
         'base/cocoa/focus_tracker_unittest.mm',
         'base/cocoa/fullscreen_window_manager_unittest.mm',
         'base/cocoa/hover_image_button_unittest.mm',
@@ -332,6 +330,12 @@
             'events/event_unittest.cc',
           ],
         }],
+        ['toolkit_views==1', {
+          'dependencies': [
+            'events/events.gyp:events',
+            'events/events.gyp:events_base',
+          ],
+        }],
         ['use_aura==1', {
           'sources!': [
             'base/dialogs/select_file_dialog_win_unittest.cc',