GN: Build rules and fixes for (almost) all mojo unittest targets

mojo/apps/js/bindings/gl/BUILD.gn

 # Copyright 2014 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.
 
 import("//mojo/system.gni")
 
-# GYP version: mojo/mojo.gyp:mojo_cc_support
-source_set("cc") {
+# GYP version: part of mojo/mojo_apps.gypi:mojo_js_lib
+source_set("gl") {
   deps = [
     "//base",
-    "//cc",
-    "//skia",
-    "//gpu/command_buffer/client:gles2_implementation",
+    "//gin",
+    "//v8",
+    "//mojo/services/gles2:bindings",
+    "//mojo/environment:chromium",
   ] + mojo_gles2_for_shared_library
 
+
   sources = [
-    "context_provider_mojo.cc",
-    "context_provider_mojo.h",
+    "context.cc",
+    "context.h",
+    "module.cc",
+    "module.h",
   ]
 }