Make a content/test API for registering JNI.

.gn

 # This file is used by the GN meta build system to find the root of the source
 # tree and to set startup options. For documentation on the values set in this
 # file, run "gn help dotfile" at the command line.
 
 # The location of the build configuration file.
 buildconfig = "//build/config/BUILDCONFIG.gn"
 
 # The secondary source root is a parallel directory tree where
 # GN build files are placed when they can not be placed directly
 # in the source tree, e.g. for third party source trees.
@@ skipping 17 matching lines @@
   "//chrome/installer/*",
   "//chrome/third_party/mozilla_security_manager/*",
   "//chromecast/*",
 
   # TODO(brettw): Fix http://crbug.com/460828 and uncomment the following
   # line.
   #"//chrome_elf/*",
   #"//cloud_print/*",
 
   #"//components/*",  # Needs nacl below.
-  #"//components:*",  # Some Android unit tests.
+  "//components:*",
   "//components/about_handler/*",
   "//components/about_ui/*",
   "//components/app_modal/*",
   "//components/audio_modem/*",
   "//components/autofill/*",
   "//components/auto_login_parser/*",
   "//components/bitmap_uploader/*",
   "//components/bookmarks/*",
   "//components/browser_sync/*",
   "//components/browser_watcher/*",
@@ skipping 297 matching lines @@
   "//tools/gn/format_test_data/055.golden",
   "//tools/gn/function_exec_script.cc",
   "//tools/gn/gn.gyp",
   "//tools/gn/input_conversion.cc",
   "//tools/gn/misc/emacs/gn.el",
   "//tools/gn/misc/vim/syntax/gn.vim",
   "//tools/gn/setup.cc",
   "//ui/accessibility/BUILD.gn",
   "//ui/views/BUILD.gn",
 ]