Provide a way to disable libpci dependency.

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 43 matching lines @@
           'use_aura%': '<(use_aura)',
           'use_ash%': '<(use_ash)',
           'use_cras%': '<(use_cras)',
           'use_ozone%': '<(use_ozone)',
           'embedded%': '<(embedded)',
           'host_arch%': '<(host_arch)',
 
           # Whether we are using Views Toolkit
           'toolkit_views%': 0,
 
+          # Use the PCI lib to collect GPU information.
+          'use_libpci%': 1,
+
           # Use OpenSSL instead of NSS as the underlying SSL and crypto
           # implementation. Certificate verification will in most cases be
           # handled by the OS. If OpenSSL's struct X509 is used to represent
           # certificates, use_openssl_certs must be set.
           'use_openssl%': 0,
 
           # Typedef X509Certificate::OSCertHandle to OpenSSL's struct X509*.
           'use_openssl_certs%': 0,
 
           # Disable viewport meta tag by default.
@@ skipping 55 matching lines @@
         },
         # Copy conditionally-set variables out one scope.
         'chromeos%': '<(chromeos)',
         'chromecast%': '<(chromecast)',
         'desktop_linux%': '<(desktop_linux)',
         'use_aura%': '<(use_aura)',
         'use_ash%': '<(use_ash)',
         'use_cras%': '<(use_cras)',
         'use_ozone%': '<(use_ozone)',
         'embedded%': '<(embedded)',
+        'use_libpci%': '<(use_libpci)',
         'use_openssl%': '<(use_openssl)',
         'use_openssl_certs%': '<(use_openssl_certs)',
         'enable_viewport%': '<(enable_viewport)',
         'enable_hidpi%': '<(enable_hidpi)',
         'buildtype%': '<(buildtype)',
         'branding%': '<(branding)',
         'host_arch%': '<(host_arch)',
         'target_arch%': '<(target_arch)',
 
         'target_subarch%': '',
@@ skipping 125 matching lines @@
       'chromecast%': '<(chromecast)',
       'host_arch%': '<(host_arch)',
       'target_arch%': '<(target_arch)',
       'target_subarch%': '<(target_subarch)',
       'mips_arch_variant%': '<(mips_arch_variant)',
       'toolkit_views%': '<(toolkit_views)',
       'desktop_linux%': '<(desktop_linux)',
       'use_aura%': '<(use_aura)',
       'use_ash%': '<(use_ash)',
       'use_cras%': '<(use_cras)',
+      'use_libpci%': '<(use_libpci)',
       'use_ozone%': '<(use_ozone)',
       'use_ozone_evdev%': '<(use_ozone_evdev)',
       'use_clipboard_aurax11%': '<(use_clipboard_aurax11)',
       'embedded%': '<(embedded)',
       'use_openssl%': '<(use_openssl)',
       'use_openssl_certs%': '<(use_openssl_certs)',
       'enable_viewport%': '<(enable_viewport)',
       'enable_hidpi%': '<(enable_hidpi)',
       'android_channel%': '<(android_channel)',
       'android_webview_build%': '<(android_webview_build)',
@@ skipping 772 matching lines @@
     'buildtype%': '<(buildtype)',
     'target_arch%': '<(target_arch)',
     'target_subarch%': '<(target_subarch)',
     'mips_arch_variant%': '<(mips_arch_variant)',
     'host_arch%': '<(host_arch)',
     'toolkit_views%': '<(toolkit_views)',
     'ui_compositor_image_transport%': '<(ui_compositor_image_transport)',
     'use_aura%': '<(use_aura)',
     'use_ash%': '<(use_ash)',
     'use_cras%': '<(use_cras)',
+    'use_libpci%': '<(use_libpci)',
     'use_openssl%': '<(use_openssl)',
     'use_openssl_certs%': '<(use_openssl_certs)',
     'use_nss%': '<(use_nss)',
     'use_udev%': '<(use_udev)',
     'os_bsd%': '<(os_bsd)',
     'os_posix%': '<(os_posix)',
     'use_dbus%': '<(use_dbus)',
     'use_glib%': '<(use_glib)',
     'use_pango%': '<(use_pango)',
     'use_cairo%': '<(use_cairo)',
@@ skipping 1842 matching lines @@
         'defines': ['ENABLE_IPC_FUZZER=1'],
       }],
       ['video_hole==1', {
         'defines': ['VIDEO_HOLE=1'],
       }],
       ['enable_load_completion_hacks==1', {
         'defines': ['ENABLE_LOAD_COMPLETION_HACKS=1'],
       }],
     ],  # conditions for 'target_defaults'
     'target_conditions': [
+      ['<(use_libpci)==1', {
+        'defines': ['USE_LIBPCI=1'],
+      }],
       ['<(use_openssl)==1', {
         'defines': ['USE_OPENSSL=1'],
       }],
       ['<(use_openssl_certs)==1', {
         'defines': ['USE_OPENSSL_CERTS=1'],
       }],
       ['>(nacl_untrusted_build)==1', {
         'defines': [
           'USE_OPENSSL=1',
           'USE_OPENSSL_CERTS=1',
@@ skipping 2890 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',
   },
 }