[counting_allocator] Chrome changes.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 1f8968670781cf0c6a810bffa6bb47170c0d8979..cd630af194ee8a1adde036421cf97d5b7dae942e 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -450,8 +450,16 @@ config("compiler") {
   }
 
   if (is_mac) {
-    cflags_cc += [ "-stdlib=libc++" ]
-    ldflags += [ "-stdlib=libc++" ]
+    if (true) {
+      cflags_cc += [
+        "-nostdinc++",
+        "-isystem" + rebase_path("//buildtools/third_party/libc++/trunk/include", root_build_dir),
+        "-isystem" + rebase_path("//buildtools/third_party/libc++abi/trunk/include", root_build_dir),
+      ]
+    } else {
+      cflags_cc += [ "-stdlib=libc++" ]
+      ldflags += [ "-stdlib=libc++" ]
+    }
   }
 
   # Add flags for link-time optimization. These flags enable