[WIP] Add DCHECK for mojo::edk::Init().

chromecast/app/BUILD.gn

Index: chromecast/app/BUILD.gn
diff --git a/chromecast/app/BUILD.gn b/chromecast/app/BUILD.gn
index cf2b992f0a471c9930ced43355c478ee3aeb0d86..2ff27f6751164b4b0689b77477b8ad3173885493 100644
--- a/chromecast/app/BUILD.gn
+++ b/chromecast/app/BUILD.gn
@@ -60,6 +60,7 @@ source_set("test_support") {
   testonly = true
   sources = [
     "cast_test_launcher.cc",
+    "cast_test_launcher.h",
   ]
 
   deps = [
@@ -68,7 +69,31 @@ source_set("test_support") {
     "//base/test:test_support",
     "//chromecast/base",
     "//content/test:test_support",
+  ]
+}
+
+source_set("unittests_main") {
+  testonly = true
+  sources = [
+    "cast_unittests_main.cc",
+  ]
+
+  deps = [
+    ":test_support",
+    "//base/test:test_support",
     "//mojo/edk/embedder:headers",
+    "//mojo/edk/test:test_support",
+  ]
+}
+
+source_set("browsertests_main") {
+  testonly = true
+  sources = [
+    "cast_browsertests_main.cc",
+  ]
+
+  deps = [
+    ":test_support",
   ]
 }