Get rid of {Run,Terminate}MainApplication(), and more ApplicationDelegate conversion.

mojo/environment/BUILD.gn

Index: mojo/environment/BUILD.gn
diff --git a/mojo/environment/BUILD.gn b/mojo/environment/BUILD.gn
index 2bf0c587c6eca2fa2352100496712f114fcee1fb..dc21a24da5b428948d368d7d2aacc9c0c18fa1f9 100644
--- a/mojo/environment/BUILD.gn
+++ b/mojo/environment/BUILD.gn
@@ -9,6 +9,8 @@ source_set("chromium") {
     "default_logger.cc",
     "default_logger.h",
     "environment.cc",
+    "scoped_chromium_init.cc",
+    "scoped_chromium_init.h",
 
     # TODO(vtl): This is kind of ugly. (See TODO in logging.h.)
     "../public/cpp/environment/async_waiter.h",