Disable deprecation warnings for CUPS as the compile fails when using CUPS 1.6

This only affects the printing module.

Current Ubuntu versions ships with CUPS 1.6 which complains about
use of deprecated CUPS methods. As we need to continue supporting
platforms using older CUPS versions such as Linux and Mac OS, we
ignore the warning as an error for now.

BUG=226176

Review URL: https://chromiumcodereview.appspot.com/14262006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@195195 0039d316-1c4b-4281-b951-d872f2087c98

printing/printing.gyp

@@ -162,12 +162,23 @@
           'dependencies': [
             'cups',
           ],
+          'variables': {
+            'cups_version': '<!(cups-config --api-version)',
+          },
           'conditions': [
             ['OS!="mac"', {
               'dependencies': [
                 '../build/linux/system.gyp:libgcrypt',
               ],
             }],
+            ['cups_version=="1.6"', {
+              'cflags': [
+                # CUPS 1.6 deprecated the PPD APIs, but we will stay with this
+                # API for now as supported Linux and Mac OS'es are still using
+                # older versions of CUPS. More info: crbug.com/226176
+                '-Wno-deprecated-declarations',
+              ],
+            }],
           ],
           'defines': [
             # PRINT_BACKEND_AVAILABLE disables the default dummy implementation