Update common.gypi to set clang=1 for all iOS builds.

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 3e2d983660be1fab5870783e1c943986dd7a6e0b..c79e8e76ee7ce79ea4b8f3becf125a1544c84c49 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -1099,11 +1099,10 @@
     'clang%': '<(clang)',
     'make_clang_dir%': 'third_party/llvm-build/Release+Asserts',
 
-    # Control which version of clang to use when 'clang' is set to 1 when
-    # building for iOS (Apple has not yet open-sourced support for "arm64"
-    # so when building for that 'target_arch' we have to use clang shipped
-    # with Xcode that does not supports some flags).
-    # TODO(sdefresne): remove this once http://crbug.com/341453 is fixed.
+    # Control which version of clang to use when building for iOS.  If set to
+    # '1', uses the version of clang that ships with Xcode.  If set to '0', uses
+    # the version of clang that ships with the Chromium source.  This variable
+    # is automatically set to '1' when using the Xcode generator.
     'clang_xcode%': 0,
 
     # These two variables can be set in GYP_DEFINES while running
@@ -1523,8 +1522,6 @@
         'jni_generator_jarjar_file': '../android_webview/build/jarjar-rules.txt',
       }],
       ['OS=="mac"', {
-        # Enable clang on mac by default!
-        'clang%': 1,
         'conditions': [
           # All Chrome builds have breakpad symbols, but only process the
           # symbols from official builds.
@@ -1534,6 +1531,9 @@
         ],
       }],  # OS=="mac"
       ['OS=="mac" or OS=="ios"', {
+        # Enable clang on mac by default!  All iOS builds already use clang.

[Nico, 2014/03/13 15:43:38]

nit: This comment can probably go away. It was (maybe) useful when clang being
on by default was noteworthy, but that was long ago.

+        'clang%': 1,
+
         'variables': {
           # Mac OS X SDK and deployment target support.  The SDK identifies
           # the version of the system headers that will be used, and
@@ -1752,16 +1752,15 @@
           '-w', '<(DEPTH)/build/ios/grit_whitelist.txt'
         ],
 
-        # Enable clang and host builds when generating with ninja-ios.
+        # Enable host builds when generating with ninja-ios.
         'conditions': [
           ['"<(GENERATOR)"=="ninja"', {
-            'clang%': 1,
             'host_os%': "mac",
           }],
-          # Apple has not upstreamed the support for "arm64" yet, so when
-          # building for "arm64" or "both", we need to use the clang that
-          # is provided with Xcode.
-          ['target_subarch!="arm32"', {
+
+          # TODO(sdefresne): Remove the target_subarch check once Apple has
+          # upstreamed the support for "arm64". http://crbug.com/341453
+          ['target_subarch!="arm32" or "<(GENERATOR)"=="xcode"', {
             'clang_xcode%': 1,
           }],
         ],
@@ -4136,23 +4135,17 @@
 
                 # Warns when a const char[] is converted to bool.
                 '-Wstring-conversion',
+
+                # Clang considers the `register` keyword as deprecated, but
+                # e.g. code generated by flex (used in angle) contains that
+                # keyword. http://crbug.com/255186
+                '-Wno-deprecated-register',
               ],
 
               'conditions': [
                 ['clang_xcode==0', {
                   'CC': '$(SOURCE_ROOT)/<(clang_dir)/clang',
                   'LDPLUSPLUS': '$(SOURCE_ROOT)/<(clang_dir)/clang++',
-
-                  'WARNING_CFLAGS': [
-                    # Clang considers the `register` keyword as deprecated, but
-                    # e.g. code generated by flex (used in angle) contains that
-                    # keyword. http://crbug.com/255186
-                    #
-                    # Note: clang as shipped with Xcode is older and does not
-                    # treat the `register` as deprecated and does not define
-                    # this flag, so don't enable it if "clang_xcode" is "1".
-                    '-Wno-deprecated-register',
-                  ],
                 }],
               ],
             }],
@@ -4426,31 +4419,9 @@
     ['OS=="ios"', {
       'target_defaults': {
         'xcode_settings' : {
-          'GCC_VERSION': 'com.apple.compilers.llvm.clang.1_0',
-
-          # This next block is mostly common with the 'mac' section above,
-          # but keying off (or setting) 'clang' isn't valid for iOS as it
-          # also means using Chromium's build of clang.
-
           # TODO(stuartmorgan): switch to c++0x (see TODOs in the clang
           # section above).
           'CLANG_CXX_LANGUAGE_STANDARD': 'gnu++0x',
-          # Warn if automatic synthesis is triggered with
-          # the -Wobjc-missing-property-synthesis flag.
-          'CLANG_WARN_OBJC_MISSING_PROPERTY_SYNTHESIS': 'YES',
-          'WARNING_CFLAGS': [
-            '-Wheader-hygiene',
-            # Don't die on dtoa code that uses a char as an array index.
-            # This is required solely for base/third_party/dmg_fp/dtoa.cc.
-            '-Wno-char-subscripts',
-            # See comment in the mac clang section above for this flag.
-            '-Wno-unneeded-internal-declaration',
-            # Match OS X clang C++11 warning settings.
-            '-Wno-c++11-narrowing',
-            # As of Xcode 5.1, the register keyword is deprecated, but Chromium
-            # code still uses it.
-            '-Wno-deprecated-register',
-          ],
 
           'conditions': [
             # Older Xcodes do not support -Wno-deprecated-register, so pass an
@@ -4460,7 +4431,7 @@
             # continue failing on unknown compiler options.
             # TODO(rohitrao): This flag is temporary and should be removed as
             # soon as the iOS bots are updated to use Xcode 5.1.
-            ['"<(GENERATOR)"=="xcode" or clang_xcode==1', {
+            ['clang_xcode==1', {
               'WARNING_CFLAGS': [
                 '-Wno-unknown-warning-option',
               ],