Disable zoom bubble for PDF extension.

chrome/chrome_tests_unit.gypi

 # Copyright 2012 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.
 {
   'variables': {
     'chrome_unit_tests_sources': [
       # histograms.xml is analyzed by AboutFlagsHistogramTest, so this
       # dependency is needed to make commit bots run unit_tests on
       # histograms.xml changes.
       '../tools/metrics/histograms/histograms.xml',
@@ skipping 2163 matching lines @@
         # Unit tests should only depend on:
         # 1) everything that the chrome binaries depend on:
         '<@(chromium_browser_dependencies)',
         '<@(chromium_child_dependencies)',
         # 2) test-specific support libraries:
         '../base/base.gyp:test_support_base',
         '../components/components_resources.gyp:components_resources',
         '../components/components.gyp:content_settings_core_test_support',
         '../components/components.gyp:password_manager_core_browser_test_support',
         '../components/components.gyp:syncable_prefs_test_support',
+        '../components/components.gyp:ui_zoom_test_support',
         '../content/content_shell_and_tests.gyp:test_support_content',
         '../content/content.gyp:content_app_both',
         '../crypto/crypto.gyp:crypto_test_support',
         '../net/net.gyp:net',
         '../net/net.gyp:net_test_support',
         '../sync/sync.gyp:test_support_sync_api',
         '../sync/sync.gyp:test_support_sync_core',
         '../sync/sync.gyp:test_support_sync_internal_api',
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
@@ skipping 779 matching lines @@
               'dependencies': [
                 '../tools/xdisplaycheck/xdisplaycheck.gyp:xdisplaycheck',
               ],
             }],
           ],
         },
       ],
     }],
   ],  # 'conditions'
 }