Enable clang and host_os when generating ninja-ios.

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 1492 matching lines @@
       ['OS=="mac"', {
         'grit_defines': ['-D', 'scale_factors=2x'],
       }],
       ['OS == "ios"', {
         'grit_defines': [
           # define for iOS specific resources.
           '-D', 'ios',
           # iOS uses a whitelist to filter resources.
           '-w', '<(DEPTH)/build/ios/grit_whitelist.txt'
         ],
+
+        # Enable clang and host builds when generating with ninja-ios.
+        'conditions': [
+          ['"<(GENERATOR)"=="ninja"', {
+            'clang%': 1,
+            'host_os%': "mac",
+          }]
+        ],
       }],
       ['enable_extensions==1', {
         'grit_defines': ['-D', 'enable_extensions'],
       }],
       ['enable_printing==1', {
         'grit_defines': ['-D', 'enable_printing'],
       }],
       ['enable_themes==1', {
         'grit_defines': ['-D', 'enable_themes'],
       }],
@@ skipping 2921 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',
   },
 }