Make RunApplication() return a MojoResult and TerminateApplication() take one.

mojo/public/cpp/utility/lib/run_loop.cc

Index: mojo/public/cpp/utility/lib/run_loop.cc
diff --git a/mojo/public/cpp/utility/lib/run_loop.cc b/mojo/public/cpp/utility/lib/run_loop.cc
index 1fde95cfecdf1d829fa2f175e9cd5c86e934a104..2f3178d7fb6e9ab70a6a5901d15e30af36192350 100644
--- a/mojo/public/cpp/utility/lib/run_loop.cc
+++ b/mojo/public/cpp/utility/lib/run_loop.cc
@@ -24,7 +24,7 @@ pthread_key_t g_current_run_loop_key;
 
 // Ensures that the "current run loop" functionality is available (i.e., that we
 // have a TLS slot).
-void EnsureCurrentRunLoopInitialized() {
+void InitializeCurrentRunLoopIfNecessary() {
   static pthread_once_t current_run_loop_key_once = PTHREAD_ONCE_INIT;
   int error = pthread_once(&current_run_loop_key_once, []() {
     int error = pthread_key_create(&g_current_run_loop_key, nullptr);
@@ -36,7 +36,7 @@ void EnsureCurrentRunLoopInitialized() {
 }
 
 void SetCurrentRunLoop(RunLoop* run_loop) {
-  EnsureCurrentRunLoopInitialized();
+  InitializeCurrentRunLoopIfNecessary();
 
   int error = pthread_setspecific(g_current_run_loop_key, run_loop);
   MOJO_ALLOW_UNUSED_LOCAL(error);
@@ -71,7 +71,7 @@ RunLoop::~RunLoop() {
 
 // static
 RunLoop* RunLoop::current() {
-  EnsureCurrentRunLoopInitialized();
+  InitializeCurrentRunLoopIfNecessary();
   return static_cast<RunLoop*>(pthread_getspecific(g_current_run_loop_key));
 }