Reworks the workspace code. Here's the new heuristics:

ash/ash.gyp

 # Copyright (c) 2012 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.
 
 {
   'variables': {
     'chromium_code': 1,
     'grit_out_dir': '<(SHARED_INTERMEDIATE_DIR)/chrome',
   },
 
@@ skipping 120 matching lines @@
         'wm/root_window_layout_manager.cc',
         'wm/root_window_layout_manager.h',
         'wm/shadow.cc',
         'wm/shadow.h',
         'wm/shadow_controller.cc',
         'wm/shadow_controller.h',
         'wm/shadow_types.cc',
         'wm/shadow_types.h',
         'wm/shelf_layout_manager.cc',
         'wm/shelf_layout_manager.h',
-        'wm/show_state_controller.h',
-        'wm/show_state_controller.cc',
         'wm/stacking_controller.cc',
         'wm/stacking_controller.h',
         'wm/status_area_layout_manager.cc',
         'wm/status_area_layout_manager.h',
         'wm/toplevel_frame_view.cc',
         'wm/toplevel_frame_view.h',
         'wm/toplevel_layout_manager.cc',
         'wm/toplevel_layout_manager.h',
         'wm/toplevel_window_event_filter.cc',
         'wm/toplevel_window_event_filter.h',
@@ skipping 16 matching lines @@
         'wm/workspace_controller.cc',
         'wm/workspace_controller.h',
         'wm/workspace/workspace.cc',
         'wm/workspace/workspace.h',
         'wm/workspace/workspace_event_filter.cc',
         'wm/workspace/workspace_event_filter.h',
         'wm/workspace/workspace_layout_manager.cc',
         'wm/workspace/workspace_layout_manager.h',
         'wm/workspace/workspace_manager.cc',
         'wm/workspace/workspace_manager.h',
-        'wm/workspace/workspace_observer.h',
       ],
     },
     {
       'target_name': 'aura_shell_unittests',
       'type': 'executable',
       'dependencies': [
         '../base/base.gyp:base',
         '../base/base.gyp:test_support_base',
         '../chrome/chrome_resources.gyp:packed_resources',
         '../build/temp_gyp/googleurl.gyp:googleurl',
@@ skipping 41 matching lines @@
         'wm/power_button_controller_unittest.cc',
         'wm/root_window_event_filter_unittest.cc',
         'wm/shadow_controller_unittest.cc',
         'wm/shelf_layout_manager_unittest.cc',
         'wm/toplevel_layout_manager_unittest.cc',
         'wm/toplevel_window_event_filter_unittest.cc',
         'wm/video_detector_unittest.cc',
         'wm/window_cycle_controller_unittest.cc',
         'wm/window_modality_controller_unittest.cc',
         'wm/workspace_controller_unittest.cc',
-        'wm/workspace/workspace_layout_manager_unittest.cc',
         'wm/workspace/workspace_manager_unittest.cc',
 
         '<(SHARED_INTERMEDIATE_DIR)/ui/gfx/gfx_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources/ui_resources.rc',
         '<(SHARED_INTERMEDIATE_DIR)/ui/ui_resources_standard/ui_resources_standard.rc',
       ],
       'conditions': [
         ['use_webkit_compositor==1', {
           'dependencies': [
             '../ui/gfx/compositor/compositor.gyp:compositor',
@@ skipping 74 matching lines @@
             'shell/cocoa/app-Info.plist',
           ],
           'xcode_settings': {
             'INFOPLIST_FILE': 'shell/cocoa/app-Info.plist',
           },
         }],
       ],
     },
   ],
 }