Use the DefaultSearchManager as the exclusive authority on DSE, ignoring Web Data.

BUG=365762
R=engedy@chromium.org, jochen@chromium.org, pkasting@chromium.org, zea@chromium.org

Review URL: https://codereview.chromium.org/268643002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@269396 0039d316-1c4b-4281-b951-d872f2087c98

• chrome/browser/profile_resetter/automatic_profile_resetter_delegate.cc[diff]
• chrome/browser/profile_resetter/automatic_profile_resetter_delegate.h[diff]
• chrome/browser/profile_resetter/automatic_profile_resetter_delegate_unittest.cc[diff]
• chrome/browser/search_engines/default_search_manager.cc[diff]
• chrome/browser/search_engines/default_search_pref_migration.cc[diff]
• chrome/browser/search_engines/default_search_pref_migration_unittest.cc[diff]
• chrome/browser/search_engines/template_url_service.cc[diff]
• chrome/browser/search_engines/template_url_service.h[diff]
• chrome/browser/search_engines/template_url_service_sync_unittest.cc[diff]
• chrome/browser/search_engines/template_url_service_test_util.cc[diff]
• chrome/browser/search_engines/template_url_service_unittest.cc[diff]
• chrome/browser/search_engines/util.cc[diff]
• chrome/browser/search_engines/util.h[diff]