printing: Adjust deprecation warning flag.

printing/BUILD.gn

Index: printing/BUILD.gn
diff --git a/printing/BUILD.gn b/printing/BUILD.gn
index fd966fea5ecf750e3fe79428483b811e69299e89..fbbf79cde972628f74133d6bf2393cf4ebb0ac8c 100644
--- a/printing/BUILD.gn
+++ b/printing/BUILD.gn
@@ -152,13 +152,16 @@ component("printing") {
       }
     }
 
-    if (is_mac && mac_sdk_version == "10.9") {
+    if (is_mac) {
       # The 10.9 SDK includes cups 1.7, which deprecates
       # httpConnectEncrypt() in favor of httpConnect2(). hhttpConnect2()
       # is new in 1.7, so it doesn't exist on OS X 10.6-10.8 and we
       # can't use it until 10.9 is our minimum system version.
       # (cups_version isn't reliable on OS X, so key the check off of
       # mac_sdk).
+      # With a 10.8 deployment target, several other APIs are deprecated.
+      # We're still on CUPS 1.4 until Linux no longer needs to support it, see
+      # comment above.
       cflags += [ "-Wno-deprecated-declarations" ]
     }