Only build extensions code in chrome/browser/ui when extensions are enabled.

chrome/chrome_browser_ui.gypi

Index: chrome/chrome_browser_ui.gypi
diff --git a/chrome/chrome_browser_ui.gypi b/chrome/chrome_browser_ui.gypi
index 9d1413ecc7add144d9160b8da4f53b5e07bf0d41..b8ed5b90693485e6ff7a2d85c0ec352b4ade6436 100644
--- a/chrome/chrome_browser_ui.gypi
+++ b/chrome/chrome_browser_ui.gypi
@@ -763,13 +763,6 @@
       'browser/ui/cocoa/wrench_menu/wrench_menu_controller.mm',
       'browser/ui/confirm_bubble.h',
       'browser/ui/crypto_module_password_dialog.h',
-      'browser/ui/extensions/accelerator_priority.cc',
-      'browser/ui/extensions/accelerator_priority.h',
-      'browser/ui/extensions/extension_installed_bubble.cc',
-      'browser/ui/extensions/extension_installed_bubble.h',
-      'browser/ui/extensions/extension_enable_flow.cc',
-      'browser/ui/extensions/extension_enable_flow.h',
-      'browser/ui/extensions/extension_enable_flow_delegate.h',
       'browser/ui/find_bar/find_bar.h',
       'browser/ui/find_bar/find_bar_state.h',
       'browser/ui/find_bar/find_bar_state_factory.cc',
@@ -1050,18 +1043,6 @@
       'browser/ui/webui/devtools_ui.h',
       'browser/ui/webui/domain_reliability_internals_ui.cc',
       'browser/ui/webui/domain_reliability_internals_ui.h',
-      'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc',
-      'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h',
-      'browser/ui/webui/extensions/extension_basic_info.cc',
-      'browser/ui/webui/extensions/extension_basic_info.h',
-      'browser/ui/webui/extensions/extension_error_ui_util.cc',
-      'browser/ui/webui/extensions/extension_error_ui_util.h',
-      'browser/ui/webui/extensions/extension_icon_source.cc',
-      'browser/ui/webui/extensions/extension_icon_source.h',
-      'browser/ui/webui/extensions/extension_info_ui.cc',
-      'browser/ui/webui/extensions/extension_info_ui.h',
-      'browser/ui/webui/extensions/pack_extension_handler.cc',
-      'browser/ui/webui/extensions/pack_extension_handler.h',
       'browser/ui/webui/favicon_source.cc',
       'browser/ui/webui/favicon_source.h',
       'browser/ui/webui/fileicon_source.cc',
@@ -2526,6 +2507,27 @@
       'browser/ui/profile_error_dialog.cc',
       'browser/ui/profile_error_dialog.h',
     ],
+    'chrome_browser_ui_extensions_sources': [
+      'browser/ui/extensions/accelerator_priority.cc',
+      'browser/ui/extensions/accelerator_priority.h',
+      'browser/ui/extensions/extension_installed_bubble.cc',
+      'browser/ui/extensions/extension_installed_bubble.h',
+      'browser/ui/extensions/extension_enable_flow.cc',
+      'browser/ui/extensions/extension_enable_flow.h',
+      'browser/ui/extensions/extension_enable_flow_delegate.h',
+      'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.cc',
+      'browser/ui/webui/extensions/chromeos/kiosk_apps_handler.h',
+      'browser/ui/webui/extensions/extension_basic_info.cc',
+      'browser/ui/webui/extensions/extension_basic_info.h',
+      'browser/ui/webui/extensions/extension_error_ui_util.cc',
+      'browser/ui/webui/extensions/extension_error_ui_util.h',
+      'browser/ui/webui/extensions/extension_icon_source.cc',
+      'browser/ui/webui/extensions/extension_icon_source.h',
+      'browser/ui/webui/extensions/extension_info_ui.cc',
+      'browser/ui/webui/extensions/extension_info_ui.h',
+      'browser/ui/webui/extensions/pack_extension_handler.cc',
+      'browser/ui/webui/extensions/pack_extension_handler.h',
+    ],
   },
   'targets': [
     {
@@ -2928,6 +2930,9 @@
             }],
           ],
         }],
+        ['enable_extensions==1', {
+          'sources': [ '<@(chrome_browser_ui_extensions_sources)' ],
+        }],
         ['enable_google_now==1 and OS!="android"', {
           'sources': [ '<@(chrome_browser_ui_google_now_non_android_sources)' ],
         }],