GN: Add mojo_shell_tests, get more things working on android

mojo/gles2/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/public/tools/bindings/mojom.gni")
+import("//mojo/system.gni")
 
+config("mojo_use_gles2") {
+  defines = [ "MOJO_USE_GLES2_IMPL" ]
+}
+
+config("gles2_use_mojo") {
+  defines = [ "USE_MOJO_GLES2" ]
+}
+
+# GYP version: mojo/mojo_base.gyp:mojo_gles2_impl
 component("gles2") {
   output_name = "mojo_gles2_impl"
 
   deps = [
     "//base",
     "//base/third_party/dynamic_annotations",
     "//gpu/command_buffer/client",
     "//gpu/command_buffer/common",
     "//gpu/command_buffer/client:gles2_implementation",
     "//mojo/public/gles2",
     "//mojo/services/gles2:bindings",
     "//mojo/services/gles2:interfaces",
     "//mojo/environment:chromium",
   ]
+  deps += mojo_system_for_component
 
-  if (is_component_build) {
-    deps += [ "//mojo/system" ]
-  }
+  defines = [
+    "MOJO_GLES2_IMPL_IMPLEMENTATION",
+    "MOJO_GLES2_IMPLEMENTATION",
+  ]
 
-  defines = [ "MOJO_GLES2_IMPL_IMPLEMENTATION" ]
+  configs += [
+    ":gles2_use_mojo",
+    ":mojo_use_gles2",
+  ]
+  direct_dependent_configs = [ ":gles2_use_mojo" ]
+  all_dependent_configs = [ ":mojo_use_gles2" ]
 
   sources = [
     "command_buffer_client_impl.cc",
     "command_buffer_client_impl.h",
     "gles2_impl_export.h",
     "gles2_impl.cc",
     "gles2_context.cc",
     "gles2_context.h",
   ]
 }