chromeos: Refactor D-Bus client creation for ash and browser processes

ash/test/ash_test_helper.cc

Index: ash/test/ash_test_helper.cc
diff --git a/ash/test/ash_test_helper.cc b/ash/test/ash_test_helper.cc
index cdb32b03ce5a9ee85d61ab777b61d1a265348ea2..6e3b8095264e5affcb27cecc74abcb67b0e35282 100644
--- a/ash/test/ash_test_helper.cc
+++ b/ash/test/ash_test_helper.cc
@@ -93,7 +93,8 @@ void AshTestHelper::SetUp(bool start_session,
 #if defined(OS_CHROMEOS)
   // Create DBusThreadManager for testing.
   if (!chromeos::DBusThreadManager::IsInitialized()) {
-    chromeos::DBusThreadManager::Initialize();
+    chromeos::DBusThreadManager::Initialize(

[James Cook, 2016/09/15 22:23:10]

By only initializing ash-process clients in ash tests we should be able to catch
future accidental usage, at least if the developer writes a test.

+        chromeos::DBusThreadManager::PROCESS_ASH);
     dbus_thread_manager_initialized_ = true;
   }