Refactor dependency on Profile to BrowserContext in spell check. Continuation of issue 23639002.

Review URL: https://chromiumcodereview.appspot.com/23868013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223699 0039d316-1c4b-4281-b951-d872f2087c98

• AUTHORS[diff]
• chrome/browser/extensions/api/spellcheck/spellcheck_api.cc[diff]
• chrome/browser/spellchecker/spellcheck_custom_dictionary_unittest.cc[diff]
• chrome/browser/spellchecker/spellcheck_factory.cc[diff]
• chrome/browser/spellchecker/spellcheck_factory.h[diff]
• chrome/browser/spellchecker/spellcheck_hunspell_dictionary.h[diff]
• chrome/browser/spellchecker/spellcheck_message_filter.cc[diff]
• chrome/browser/spellchecker/spellcheck_message_filter_mac.cc[diff]
• chrome/browser/spellchecker/spellcheck_service.cc[diff]
• chrome/browser/spellchecker/spellcheck_service.h[diff]
• chrome/browser/spellchecker/spellcheck_service_browsertest.cc[diff]
• chrome/browser/spellchecker/spelling_service_client.cc[diff]
• chrome/browser/spellchecker/spelling_service_client.h[diff]
• chrome/browser/sync/profile_sync_components_factory_impl.cc[diff]
• chrome/browser/sync/test/integration/dictionary_helper.cc[diff]
• chrome/browser/tab_contents/spelling_menu_observer.cc[diff]
• chrome/browser/ui/webui/options/language_dictionary_overlay_handler.cc[diff]
• chrome/browser/ui/webui/options/language_options_handler_common.cc[diff]