Add some simple HTMLViewer apptests.

BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This is the root build file for GN. GN will start processing by loading this
 # file, and recursively load all dependencies until all dependencies are either
 # resolved or known not to exist (which will cause the build to fail). So if
 # you add a new build file, there must be some path of dependencies from this
 # file to your new one or GN won't know about it.
 
@@ skipping 558 matching lines @@
       "//third_party/mojo/src/mojo/edk/js/tests:js_to_cpp_bindings_python",
       "//third_party/mojo/src/mojo/public/python:packaged_application",
       "//third_party/mojo/src/mojo/public/python:packaged_bindings",
       "//third_party/mojo/src/mojo/public/cpp/application:test_support_standalone",
       "//third_party/mojo_services/src/accessibility/public/interfaces:interfaces_dart",
       "//third_party/mojo_services/src/accessibility/public/interfaces:interfaces_python",
       "//third_party/mojo_services/src/window_manager/public/interfaces:interfaces_dart",
       "//third_party/mojo_services/src/window_manager/public/interfaces:interfaces_python",
     ]
 
-    if (!is_debug) {

[sky, 2015/04/02 16:56:17]

Wow, this is weird. I wonder why we had these two in only release mode?

+    #if (!is_debug) {
       deps += [
         "//mojo/services/html_viewer:tests",
+        "//mojo/services/html_viewer:apptests",
         "//mojo/services/network:apptests",
       ]
-    }
+    #}
   }
 }
 
 group("gn_visibility") {
   deps = [
     # "//build/config/sanitizers:options_sources",
     # "//third_party/pdfium:pdfium_embeddertests",  # TODO(GYP): visibility?
     # "//third_party/pdfium:pdfium_unittests",  # TODO(GYP): visibility?
     # "//ui/resources:repack_ui_test_mac_locale_pack",
     # "//v8:v8_snapshot",  # TODO(GYP): visibility?
@@ skipping 60 matching lines @@
       "//ui/touch_selection:ui_touch_selection_unittests",  # PASSES 2/25/2015
       "//ui/views:views_unittests",  # PASSES (*) 2/25/2015
       "//ui/wm:wm_unittests",  # PASSES 2/25/2015
       "//url:url_unittests",  # PASSES 2/25/2015
 
       # Note:
       # (*) Fails but failures match GYP build at time of testing.
     ]
   }
 }