Implement ScreenOrientationDelegate on ChromeOS

ash/ash.gyp

Index: ash/ash.gyp
diff --git a/ash/ash.gyp b/ash/ash.gyp
index 8a8c36edc4c8826cef872695afbf7ef84db81a98..47c268c7638b6dea8df87ce0d87651667587a547 100644
--- a/ash/ash.gyp
+++ b/ash/ash.gyp
@@ -47,6 +47,8 @@
       'ash_touch_exploration_manager_chromeos.h',
       'cancel_mode.cc',
       'cancel_mode.h',
+      'content/display/screen_orientation_delegate_chromeos.cc',
+      'content/display/screen_orientation_delegate_chromeos.h',
       'debug.cc',
       'debug.h',
       'default_accessibility_delegate.cc',
@@ -771,6 +773,7 @@
       'accelerators/spoken_feedback_toggler_unittest.cc',
       'ash_touch_exploration_manager_chromeos_unittest.cc',
       'autoclick/autoclick_unittest.cc',
+      'content/display/screen_orientation_delegate_chromeos_unittest.cc',
       'desktop_background/desktop_background_controller_unittest.cc',
       'desktop_background/wallpaper_resizer_unittest.cc',
       'dip_unittest.cc',
@@ -1119,6 +1122,7 @@
       'conditions': [
         ['chromeos==0', {
           'sources!': [
+            'content/display/screen_orientation_delegate_chromeos_unittest.cc',
             # TODO(zork): fix this test to build on Windows. See: crosbug.com/26906
             'focus_cycler_unittest.cc',
             # All tests for multiple displays: not supported on Windows Ash.