Fix valgrind bot errors introduced in f84722e4777.

gyp/zlib.gyp

 # Copyright 2014 Google Inc.
 #
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'skia_warnings_as_errors': 0,
   },
   'targets': [
     {
       'target_name': 'zlib',
       'conditions': [
         [ 'skia_zlib_static',
           {
             'type': 'static_library',
             'include_dirs': [
               '../third_party/externals/zlib',
             ],
             'direct_dependent_settings': {
               'defines': [
-                'SK_ZLIB_INCLUDE=<zlib.h>',
+                'SK_ZLIB_INCLUDE="zlib.h"',
               ],
               'include_dirs': [
                 '../third_party/externals/zlib',
               ],
             },
             'sources': [
               '../third_party/externals/zlib/src/adler32.c',
               '../third_party/externals/zlib/src/compress.c',
               '../third_party/externals/zlib/src/crc32.c',
               '../third_party/externals/zlib/src/deflate.c',
@@ skipping 12 matching lines @@
           }, {  # not skia_zlib_static
             'type': 'none',
             'direct_dependent_settings': {
               'conditions': [
                 [ 'skia_android_framework', {
                   'include_dirs': [
                     'external/zlib',
                   ],
                 }, {
                   'defines': [
-                    'SK_ZLIB_INCLUDE=<zlib.h>',
+                    'SK_SYSTEM_ZLIB=1',
                   ],
                 }]
               ],
               'link_settings': {
                 'conditions': [
                   [ 'skia_os == "mac" or skia_os == "ios"', {
                     'libraries': [
                       '$(SDKROOT)/usr/lib/libz.dylib',
                     ]
                   }, {  # skia_os != "mac" and skia_os != "ios"
                     'libraries': [
                       '-lz',
                     ]
                   }],
                 ],
               }
             },
           }
         ]
       ]
     }
   ]
 }