Disable zoom bubble for PDF extension.

chrome/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/compiler/compiler.gni")
 import("//build/config/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//chrome/chrome_tests.gni")
@@ skipping 99 matching lines @@
     "//components/omnibox/browser:test_support",
     "//components/password_manager/core/browser:test_support",
     "//components/pref_registry:test_support",
     "//components/rappor:test_support",
     "//components/search_engines:test_support",
     "//components/signin/core/browser:test_support",
     "//components/sync_driver:test_support",
     "//components/sync_sessions:test_support",
     "//components/syncable_prefs:test_support",
     "//components/update_client:test_support",
+    "//components/ui/zoom:test_support",
     "//content/public/app:both",
     "//ui/gfx:test_support",
     "//net",
     "//net:test_support",
     "//skia",
     "//sql",
     "//sql:test_support",
     "//sync",
     "//testing/gmock",
     "//testing/gtest",
@@ skipping 2035 matching lines @@
     "//third_party/mojo/src/mojo/edk/system",
   ]
 
   if (!is_android && use_ash) {
     sources += rebase_path(
             chrome_tests_unit_gypi_values.chrome_test_support_unit_ash_sources,
             ".",
             "//chrome")
   }
 }