Add support for libxml as a system library target on iOS

third_party/libxml/libxml.gyp

 # 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.
 
 {
   'variables': {
     'conditions': [
       # Define an "os_include" variable that points at the OS-specific generated
       # headers.  These were generated by running the configure script offline.
-      ['os_posix == 1 and OS != "mac"', {
+      ['os_posix == 1 and OS != "mac" and OS != "ios"', {
         'os_include': 'linux'
       }],
       ['OS=="mac"', {'os_include': 'mac'}],
       ['OS=="win"', {'os_include': 'win32'}],
     ],
     'use_system_libxml%': 0,
   },
   'targets': [
     {
       'target_name': 'libxml',
       'conditions': [
-        ['os_posix == 1 and OS != "mac" and use_system_libxml', {
+        ['use_system_libxml', {
+          'conditions': [
+            ['os_posix == 1 and OS != "mac" and OS != "ios"', {
+              'type': 'static_library',
+              'sources': [
+                'chromium/libxml_utils.h',
+                'chromium/libxml_utils.cc',
+              ],
+              'cflags': [
+                '<!@(pkg-config --cflags libxml-2.0)',
+              ],
+              'defines': [
+                'USE_SYSTEM_LIBXML',
+              ],
+              'direct_dependent_settings': {
+                'cflags': [
+                  '<!@(pkg-config --cflags libxml-2.0)',
+                ],
+                'defines': [
+                  'USE_SYSTEM_LIBXML',
+                ],
+              },
+              'link_settings': {
+                'ldflags': [
+                  '<!@(pkg-config --libs-only-L --libs-only-other libxml-2.0)',
+                ],
+                'libraries': [
+                  '<!@(pkg-config --libs-only-l libxml-2.0)',
+                ],
+              },
+            }],
+            ['OS == "ios"', {
+              'type': 'none',
+              'all_dependent_settings': {
+                'defines': [
+                  'USE_SYSTEM_LIBXML',
+                ],
+                'include_dirs': [
+                  '$(SDKROOT)/usr/include/libxml2',
+                ],
+              },
+              'link_settings': {
+                'libraries': [
+                  '$(SDKROOT)/usr/lib/libxml2.dylib',
+                ],
+              },
+            }],
+          ],
+        }, {  # else: !use_system_libxml
           'type': 'static_library',
           'sources': [
             'chromium/libxml_utils.h',
-            'chromium/libxml_utils.cc',
-          ],
-          'cflags': [
-            '<!@(pkg-config --cflags libxml-2.0)',
-          ],
-          'defines': [
-            'USE_SYSTEM_LIBXML',
-          ],
-          'direct_dependent_settings': {
-            'cflags': [
-              '<!@(pkg-config --cflags libxml-2.0)',
-            ],
-            'defines': [
-              'USE_SYSTEM_LIBXML',
-            ],
-          },
-          'link_settings': {
-            'ldflags': [
-              '<!@(pkg-config --libs-only-L --libs-only-other libxml-2.0)',
-            ],
-            'libraries': [
-              '<!@(pkg-config --libs-only-l libxml-2.0)',
-            ],
-          },
-        }, { # else: os_posix != 1 or OS == "mac" or ! use_system_libxml
-          'type': 'static_library',
-          'sources': [
-            'chromium/libxml_utils.h',
             'chromium/libxml_utils.cc',
             'linux/config.h',
             'linux/include/libxml/xmlversion.h',
             'mac/config.h',
             'mac/include/libxml/xmlversion.h',
             'src/include/libxml/c14n.h',
             'src/include/libxml/catalog.h',
             'src/include/libxml/chvalid.h',
             'src/include/libxml/debugXML.h',
             'src/include/libxml/dict.h',
@@ skipping 160 matching lines @@
                 '-Wno-pointer-sign',
                 '-Wno-empty-body',
               ],
             }],
           ],
         }],
       ],
     },
   ],
 }