Set cc_flags for cmake build on Mac

gyp/common_conditions.gypi

 # Copyright 2015 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # conditions used in both common.gypi and skia.gyp in chromium
 #
 {
   'defines': [
     'SK_ALLOW_STATIC_GLOBAL_INITIALIZERS=<(skia_static_initializers)',
@@ skipping 501 matching lines @@
                 '-include <(skia_sanitizer_blacklist)',             # Make every .cpp depend on it.
               ],
               # We want to pass -fsanitize=... to our final link call,
               # but not to libtool. OTHER_LDFLAGS is passed to both.
               # To trick GYP into doing what we want, we'll piggyback on
               # LIBRARY_SEARCH_PATHS, producing "-L/usr/lib -fsanitize=...".
               # The -L/usr/lib is redundant but innocuous: it's a default path.
               'LIBRARY_SEARCH_PATHS': [ '/usr/lib -fsanitize=<(skia_sanitizer)'],
             }],
           ],
+          # Keep these in sync with cflags_cc below
           'CLANG_CXX_LIBRARY':                         'libc++',
           'CLANG_CXX_LANGUAGE_STANDARD':               'c++11',
           'GCC_ENABLE_CPP_EXCEPTIONS':                 'NO',   # -fno-exceptions
           'GCC_ENABLE_CPP_RTTI':                       'NO',   # -fno-rtti
           'GCC_THREADSAFE_STATICS':                    'NO',   # -fno-threadsafe-statics
           'GCC_ENABLE_SUPPLEMENTAL_SSE3_INSTRUCTIONS': 'YES',  # -mssse3
           'GCC_SYMBOLS_PRIVATE_EXTERN':                'NO',   # -fvisibility=hidden
           'GCC_INLINES_ARE_PRIVATE_EXTERN':            'NO',   # -fvisibility-inlines-hidden
           'GCC_CW_ASM_SYNTAX':                         'NO',   # remove -fasm-blocks
           'GCC_ENABLE_PASCAL_STRINGS':                 'NO',   # remove -mpascal-strings
           'WARNING_CFLAGS': [

[mtklein, 2016/01/22 16:14:18]

One trick I've often considered is that any cflags can go in here, not just
warning flags.

We could pile most things into a variable that we then expand into
WARNING_CFLAGS and 'cflags', removing most of these CLANG_ and GCC_ one-off
settings for the version in comments on the right.

That doesn't help C++-specific flags, like -std=c++11 and -fnortti. 
WARNING_CFLAGS is used for C and C++ code alike.

[bsalomon, 2016/01/22 16:25:34]

With Herb's change to gyp --std=c++11 is applied to all the cmake C++ compiles,
but these other flags are not (WARNING_CFLAGS and CLANG_/GCC_ settings alike).
So something like that seems like a step forward.

             '-Wall',
             '-Wextra',
             '-Winit-self',
             '-Wpointer-arith',
             '-Wsign-compare',
 
             '-Wno-unused-parameter',
           ],
         },
+        # Keep these in sync with xcode settings above
+        'cflags_cc': [
+          '-std=c++11',
+          '-fno-rtti',
+          '-fno-threadsafe-statics',
+          '-mssse3',
+          '-fvisibility=hidden',
+          '-fvisibility-inlines-hidden',
+          '-Wall',
+          '-Wextra',
+          '-Winit-self',
+          '-Wpointer-arith',
+          '-Wsign-compare',
+          '-Wno-unused-parameter',
+        ],
       },
     ],
 
     [ 'skia_os == "ios"',
       {
         'defines': [
           'SK_BUILD_FOR_IOS',
         ],
         'conditions' : [
           [ 'skia_warnings_as_errors', {
@@ skipping 108 matching lines @@
           'LD_RUNPATH_SEARCH_PATHS': ['@executable_path/.'],
       },
     }],
 
   ], # end 'conditions'
   # The Xcode SYMROOT must be at the root. See build/common.gypi in chromium for more details
   'xcode_settings': {
     'SYMROOT': '<(DEPTH)/xcodebuild',
   },
 }