Add a unit test for Hunspell spellcheck

DEPS

 # When adding a new dependency, please update the top-level .gitignore file
 # to list the dependency's destination directory.
 
 vars = {
   # Use this googlecode_url variable only if there is an internal mirror for it.
   # If you do not know, use the full path while defining your new deps entry.
   "googlecode_url": "http://%s.googlecode.com/svn",
   "sourceforge_url": "http://%(repo)s.svn.sourceforge.net/svnroot/%(repo)s",
   "webkit_trunk": "http://svn.webkit.org/repository/webkit/trunk",
   "nacl_trunk": "http://src.chromium.org/native_client/trunk",
@@ skipping 67 matching lines @@
   "src/third_party/WebKit":
     "/trunk/deps/third_party/WebKit@76115",
 
   "src/third_party/icu":
     "/trunk/deps/third_party/icu46@182486",
 
   "src/third_party/libexif/sources":
     "/trunk/deps/third_party/libexif/sources@146817",
 
   "src/third_party/hunspell":
-   "/trunk/deps/third_party/hunspell@177853",
+   "/trunk/deps/third_party/hunspell@184822",
 
   "src/third_party/hunspell_dictionaries":
     "/trunk/deps/third_party/hunspell_dictionaries@175986",
 
   "src/third_party/safe_browsing/testing":
     (Var("googlecode_url") % "google-safe-browsing") + "/trunk/testing@112",
 
   "src/third_party/cacheinvalidation/src":
     (Var("googlecode_url") % "google-cache-invalidation-api") +
     "/trunk/src@273",
@@ skipping 576 matching lines @@
     # A change to a .gyp, .gypi, or to GYP itself should run the generator.
     "pattern": ".",
     "action": ["python", "src/build/gyp_chromium"],
   },
   {
     # Check for landmines (reasons to clobber the build).
     "pattern": ".",
     "action": ["python", "src/build/landmines.py"],
   },
 ]