proof of concept for building with libc++

build/common.gypi

Index: build/common.gypi
diff --git a/build/common.gypi b/build/common.gypi
index 31bf1c47428392e53769a961a1e8eb3f337ea715..7040f881bc537e91854ff53f7e24bb9c88984fe1 100644
--- a/build/common.gypi
+++ b/build/common.gypi
@@ -3271,6 +3271,22 @@
                 # also contain a default: branch. Chrome is full of that.
                 '-Wno-covered-switch-default',
               ],
+              'OTHER_CFLAGS': [
+                '-stdlib=libc++',
+                '-I/Users/thakis/src/libcxx/include/',
+                '-I/Users/thakis/src/libcxxabi/include/',
+                '-Wno-#warnings',  # For the deprecation warning in ext/hash_map
+              ],
+              'target_conditions': [
+                ['_type!="static_library"', {
+                  'OTHER_LDFLAGS': [
+                    '-nodefaultlibs',
+                    '~/src/libcxx/lib/libc++.a',
+                    '~/src/libcxxabi/lib/libc++abi.a',
+                    '-lSystem',
+                  ],
+                }],
+              ],
               'OTHER_CPLUSPLUSFLAGS': [
                 # gnu++11 instead of c++11 so that __ANSI_C__ doesn't get
                 # defined.  (Else e.g. finite() in base/float_util.h needs to