Add chrome_split_dll gyp variable, and duplicate chrome_main_dll target (reland)

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.
 {
   'targets': [
     {
       # This target contains mocks and test utilities that don't belong in
       # production libraries but are used by more than one test executable.
       'target_name': 'test_support_common',
       'type': 'static_library',
@@ skipping 395 matching lines @@
       ],
     },
     {
       'target_name': 'unit_tests',
       'type': '<(gtest_target_type)',
       'dependencies': [
         # NOTE: New dependencies should generally be added in the OS!="ios"
         # dependencies block below, rather than here.
         # Unit tests should only depend on:
         # 1) everything that the chrome binaries depend on:
-        '<@(chromium_dependencies)',
+        '<@(chromium_browser_dependencies)',
+        '<@(chromium_child_dependencies)',
         # 2) test-specific support libraries:
         '../base/base.gyp:test_support_base',
         '../media/media.gyp:media_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',
         '../sync/sync.gyp:test_support_sync_notifier',
         '../testing/gmock.gyp:gmock',
@@ skipping 1960 matching lines @@
           ],
         }],
       ],
     },
     {
       'target_name': 'chrome_app_unittests',
       'type': 'executable',
       'dependencies': [
         # unit tests should only depend on
         # 1) everything that the chrome binaries depend on:
-        '<@(chromium_dependencies)',
+        '<@(chromium_browser_dependencies)',
+        '<@(chromium_child_dependencies)',
         # 2) test-specific support libraries:
         '../testing/gmock.gyp:gmock',
         '../testing/gtest.gyp:gtest',
         'test_support_common',
       ],
       'include_dirs': [
         '..',
       ],
       'sources': [
         'app/breakpad_field_trial_win.cc',
@@ skipping 88 matching lines @@
               # more details.
               'DebugInformationFormat': '3',
               'ProgramDataBaseFileName': '<(PRODUCT_DIR)/unit_tests.exe.pdb',
             },
           },
         },
       ],
     }],
   ],  # 'conditions'
 }