Add ui/display, message_center, webview to GN build.

ui/display/display.gyp

Index: ui/display/display.gyp
diff --git a/ui/display/display.gyp b/ui/display/display.gyp
index 56fcb204fe078e2411856c15342f6fa6c2108423..ef2dddfa2ffb1f10b1b9099dea11072239c774de 100644
--- a/ui/display/display.gyp
+++ b/ui/display/display.gyp
@@ -8,6 +8,7 @@
   },
   'targets': [
     {
+      # GN version: //ui/display/types
       'target_name': 'display_types',
       'type': '<(component)',
       'dependencies': [
@@ -18,6 +19,7 @@
         'DISPLAY_TYPES_IMPLEMENTATION',
       ],
       'sources': [
+        # Note: file list duplicated in GN build.
         'types/chromeos/display_mode.cc',
         'types/chromeos/display_mode.h',
         'types/chromeos/display_snapshot.cc',
@@ -32,6 +34,7 @@
       ],
     },
     {
+      # GN version: //ui/display
       'target_name': 'display',
       'type': '<(component)',
       'dependencies': [
@@ -44,6 +47,7 @@
         'DISPLAY_IMPLEMENTATION',
       ],
       'sources': [
+        # Note: file list duplicated in GN build.
         'chromeos/display_configurator.cc',
         'chromeos/display_configurator.h',
         'chromeos/touchscreen_delegate_impl.cc',
@@ -89,6 +93,7 @@
       ],
     },
     {
+      # GN version: //ui/display/util
       'target_name': 'display_util',
       'type': '<(component)',
       'dependencies': [
@@ -99,6 +104,7 @@
         'DISPLAY_UTIL_IMPLEMENTATION',
       ],
       'sources': [
+        # Note: file list shared with GN build.
         'util/display_util.cc',
         'util/display_util.h',
         'util/display_util_export.h',
@@ -122,6 +128,7 @@
       ],
     },
     {
+      # GN version: //ui/display:test_util
       'target_name': 'display_test_util',
       'type': '<(component)',
       'dependencies': [
@@ -133,6 +140,7 @@
         'DISPLAY_IMPLEMENTATION',
       ],
       'sources': [
+        # Note: file list duplicated in GN build.
         'chromeos/test/test_display_snapshot.cc',
         'chromeos/test/test_display_snapshot.h',
       ],
@@ -145,6 +153,7 @@
       ],
     },
     {
+      # GN version: //ui/display:display_unittests
       'target_name': 'display_unittests',
       'type': 'executable',
       'dependencies': [