Remove the enable_metro GYP flag, effectively making it on by default.

build/common.gypi

 # 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.
 
 # IMPORTANT:
 # Please don't directly include this file if you are building via gyp_chromium,
 # since gyp_chromium is automatically forcing its inclusion.
 {
   # Variables expected to be overriden on the GYP command line (-D) or by
   # ~/.gyp/include.gypi.
@@ skipping 25 matching lines @@
 
           # Disable viewport meta tag by default.
           'enable_viewport%': 0,
 
           # Enable HiDPI support.
           'enable_hidpi%': 0,
 
           # Enable touch optimized art assets and metrics.
           'enable_touch_ui%': 0,
 
-          # Enable inclusion of touch-optimized resources.
-          # TODO(joi): Rename to enable_touch_assets.
-          'enable_metro%': 0,
-
           # Is this change part of the android upstream bringup?
           # Allows us to *temporarily* disable certain things for
           # staging.  Only set to 1 in a GYP_DEFINES.
           'android_upstream_bringup%': 0,
 
           # Override buildtype to select the desired build flavor.
           # Dev - everyday build for development/testing
           # Official - release build (generally implies additional processing)
           # TODO(mmoss) Once 'buildtype' is fully supported (e.g. Windows gyp
           # conversion is done), some of the things which are now controlled by
           # 'branding', such as symbol generation, will need to be refactored
           # based on 'buildtype' (i.e. we don't care about saving symbols for
           # non-Official # builds).
           'buildtype%': 'Dev',
         },
         # Copy conditionally-set variables out one scope.
         'chromeos%': '<(chromeos)',
         'use_aura%': '<(use_aura)',
         'use_ash%': '<(use_ash)',
         'use_openssl%': '<(use_openssl)',
         'use_ibus%': '<(use_ibus)',
         'enable_viewport%': '<(enable_viewport)',
         'enable_hidpi%': '<(enable_hidpi)',
         'enable_touch_ui%': '<(enable_touch_ui)',
-        'enable_metro%': '<(enable_metro)',
         'android_upstream_bringup%': '<(android_upstream_bringup)',
         'buildtype%': '<(buildtype)',
 
         # Compute the architecture that we're building on.
         'conditions': [
           [ 'OS=="win" or OS=="mac"', {
             'host_arch%': 'ia32',
           }, {
             # This handles the Unix platforms for which there is some support.
             # Anything else gets passed through, which probably won't work very
@@ skipping 25 matching lines @@
           }, {
             'toolkit_views%': 0,
           }],
 
           # Enable HiDPI on Mac OS.
           ['OS=="mac"', {
             'enable_hidpi%': 1,
           }],
 
           # Enable touch UI on Metro and Chrome OS.
-          ['enable_metro==1 or chromeos==1', {
+          ['OS=="win" or chromeos==1', {
             'enable_touch_ui%': 1,
           }],
         ],
       },
 
       # Copy conditionally-set variables out one scope.
       'chromeos%': '<(chromeos)',
       'host_arch%': '<(host_arch)',
       'toolkit_views%': '<(toolkit_views)',
       'use_aura%': '<(use_aura)',
       'use_ash%': '<(use_ash)',
       'use_openssl%': '<(use_openssl)',
       'use_ibus%': '<(use_ibus)',
       'enable_viewport%': '<(enable_viewport)',
       'enable_hidpi%': '<(enable_hidpi)',
       'enable_touch_ui%': '<(enable_touch_ui)',
-      'enable_metro%': '<(enable_metro)',
       'android_upstream_bringup%': '<(android_upstream_bringup)',
 
       # We used to provide a variable for changing how libraries were built.
       # This variable remains until we can clean up all the users.
       # This needs to be one nested variables dict in so that dependent
       # gyp files can make use of it in their outer variables.  (Yikes!)
       # http://code.google.com/p/chromium/issues/detail?id=83308
       'library%': 'static_library',
 
       # Override branding to select the desired branding flavor.
@@ skipping 377 matching lines @@
     'use_skia%': '<(use_skia)',
     'use_x11%': '<(use_x11)',
     'use_gnome_keyring%': '<(use_gnome_keyring)',
     'linux_fpic%': '<(linux_fpic)',
     'enable_pepper_threading%': '<(enable_pepper_threading)',
     'build_ppapi_ipc_proxy_untrusted%': '<(build_ppapi_ipc_proxy_untrusted)',
     'chromeos%': '<(chromeos)',
     'enable_viewport%': '<(enable_viewport)',
     'enable_hidpi%': '<(enable_hidpi)',
     'enable_touch_ui%': '<(enable_touch_ui)',
-    'enable_metro%': '<(enable_metro)',
     'use_xi2_mt%':'<(use_xi2_mt)',
     'file_manager_extension%': '<(file_manager_extension)',
     'webui_task_manager%': '<(webui_task_manager)',
     'inside_chromium_build%': '<(inside_chromium_build)',
     'fastbuild%': '<(fastbuild)',
     'dcheck_always_on%': '<(dcheck_always_on)',
     'python_ver%': '<(python_ver)',
     'armv7%': '<(armv7)',
     'arm_neon%': '<(arm_neon)',
     'sysroot%': '<(sysroot)',
@@ skipping 798 matching lines @@
       }],
       ['input_speech==1', {
         'defines': ['ENABLE_INPUT_SPEECH'],
       }],
       ['notifications==1', {
         'defines': ['ENABLE_NOTIFICATIONS'],
       }],
       ['enable_hidpi==1', {
         'defines': ['ENABLE_HIDPI=1'],
       }],
-      ['enable_metro==1', {
-        'defines': ['ENABLE_METRO=1'],
-      }],
       ['OS=="android" and gtest_target_type=="shared_library"', {
         'defines': ['ANDROID_APK_TEST_TARGET=1'],
       }],
       ['fastbuild!=0', {
 
         'conditions': [
           # For Windows and Mac, we don't genererate debug information.
           ['OS=="win" or OS=="mac"', {
             'msvs_settings': {
               'VCLinkerTool': {
@@ skipping 1751 matching lines @@
     # settings in target dicts.  SYMROOT is a special case, because many other
     # Xcode variables depend on it, including variables such as
     # PROJECT_DERIVED_FILE_DIR.  When a source group corresponding to something
     # like PROJECT_DERIVED_FILE_DIR is added to a project, in order for the
     # files to appear (when present) in the UI as actual files and not red
     # red "missing file" proxies, the correct path to PROJECT_DERIVED_FILE_DIR,
     # and therefore SYMROOT, needs to be set at the project level.
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }