mojo: first take on removing mojo_main_{chromium,standalone}.

mojo/public/cpp/application/BUILD.gn

Index: mojo/public/cpp/application/BUILD.gn
diff --git a/mojo/public/cpp/application/BUILD.gn b/mojo/public/cpp/application/BUILD.gn
index 12afb5cd98022f7be1be1bfb66ce942b29ebf73d..ab42e1bae9e0ab47dce987a057bce7fa0b3f6024 100644
--- a/mojo/public/cpp/application/BUILD.gn
+++ b/mojo/public/cpp/application/BUILD.gn
@@ -23,7 +23,7 @@ source_set("base") {
 
 source_set("chromium") {
   sources = [
-    "lib/application_impl_chromium.cc"
+    "lib/application_runner_chromium.cc"
   ]
 
   deps = [ ":base" ]
@@ -31,24 +31,8 @@ source_set("chromium") {
 
 source_set("standalone") {
   sources = [
-    "lib/application_impl_standalone.cc"
+    "lib/application_runner.cc"
   ]
 
   deps = [ ":base" ]
 }
-
-source_set("main_chromium") {
-  sources = [
-    "lib/mojo_main_chromium.cc"
-  ]
-
-  deps = [ ":chromium" ]
-}
-
-source_set("main_standalone") {
-  sources = [
-    "lib/mojo_main_standalone.cc"
-  ]
-
-  deps = [ ":standalone" ]
-}