add missing zlib dep after CL 1148633007

content/test/BUILD.gn

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//build/config/chrome_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/module_args/v8.gni")
 import("//testing/test.gni")
@@ skipping 286 matching lines @@
       "//ppapi/shared_impl",
       "//third_party/mojo/src/mojo/edk/system",
       "//third_party/mojo/src/mojo/edk/test:test_support",
       "//third_party/mojo/src/mojo/public/cpp/bindings",
       "//third_party/mojo/src/mojo/public/js",
       "//testing/gmock",
       "//testing/gtest",
       "//third_party/WebKit/public:blink",
       "//third_party/leveldatabase",
       "//third_party/mesa:osmesa",
+      "//third_party/zlib",
       "//ui/accessibility",
       "//ui/accessibility:ax_gen",
       "//ui/base",
       "//ui/base/ime",
       "//ui/gfx",
       "//ui/gfx/geometry",
       "//ui/gl",
       "//ui/resources",
       "//ui/shell_dialogs",
       "//ui/snapshot",
@@ skipping 380 matching lines @@
       "//gpu/blink",
       "//testing/gtest",
       "//third_party/WebKit/public:blink",
       "//ui/base",
       "//ui/gfx",
       "//ui/gfx/geometry",
       "//ui/gl",
     ]
   }
 }