Add spell checking support (issue #137).

This includes:
- Red underline of misspelled words in html text areas.
- Right-click context menu options to correct the misspelled word.
- New CefBrowser::ReplaceMisspelling method for accepting a word replacement.
- Methods added to CefContextMenuParams for retrieving spelling-related information.
- Uses the unified text checker when auto-correct is not enabled to match Google Chrome behavior.
- On Windows and Linux a hunspell dictionary file will be downloaded to the "<cache_path>/Dictionaries" directory as needed, or used from the <cache_path> directory if the file already exists there. The dictionary file will be downloaded from http://cache.pack.google.com/edgedl/chrome/dict/<LANG>-3-0.bdic where <LANG> is the language abbreviation.
- On OS X the spell checking implementation will use the system NSSpellChecker implementation.

The following command-line flags have been added:
--disable-spell-checking => Disable spell-checking support (no red underline, no dictionary file download, etc).
--enable-spelling-auto-correct => Automatically correct common misspellings while typing (like 'omre' to 'more' on Windows/Linux or 'ehlo' to 'helo' on OS X).
--enable-spelling-service => Enable use of the remote Google spelling service (this requires Google API keys).
--override-spell-check-lang=<LANG> => Use the specified dictionary language <LANG> instead of the language specified in the locales.pak file. To see the default/supported dictionary languages: https://code.google.com/p/chromium/codesearch#search/&q=IDS_SPELLCHECK_DICTIONARY%20xtb&sq=package:chromium


git-svn-id: https://chromiumembedded.googlecode.com/svn/trunk@1859 5089003a-bbd8-11dd-ad1f-f1f9622dbc98

libcef/browser/browser_main.cc

@@ -17,6 +17,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_number_conversions.h"
 #include "chrome/browser/net/proxy_service_factory.h"
+#include "components/user_prefs/user_prefs.h"
 #include "content/browser/webui/content_web_ui_controller_factory.h"
 #include "content/public/browser/gpu_data_manager.h"
 #include "content/public/browser/web_ui_controller_factory.h"
@@ -149,6 +150,8 @@ void CefBrowserMainParts::PreMainMessageLoopRun() {
       LOG(WARNING) << "Invalid http debugger port number " << port;
     }
   }
+
+  user_prefs::UserPrefs::Set(browser_context(), pref_service());
 }
 
 void CefBrowserMainParts::PostMainMessageLoopRun() {