[Service Manager] Get rid of dynamic service discovery

mash/runner/main.cc

Index: mash/runner/main.cc
diff --git a/mash/runner/main.cc b/mash/runner/main.cc
index 0da41cd783d6cfc770cea9fa5e4a8c94505adf7c..4a05e34bac31a44f11c7ae47f29ec292af6c9622 100644
--- a/mash/runner/main.cc
+++ b/mash/runner/main.cc
@@ -21,7 +21,10 @@
 #include "base/process/launch.h"
 #include "base/run_loop.h"
 #include "base/threading/platform_thread.h"
+#include "base/threading/thread.h"
 #include "build/build_config.h"
+#include "mojo/edk/embedder/embedder.h"
+#include "mojo/edk/embedder/scoped_ipc_support.h"
 #include "services/service_manager/runner/init.h"
 #include "services/service_manager/standalone/context.h"
 #include "services/service_manager/switches.h"
@@ -58,33 +61,33 @@ int main(int argc, char** argv) {
       base::JSONReader::Read(catalog_contents);
   DCHECK(manifest_value);
 
-  auto params = base::MakeUnique<service_manager::Context::InitParams>();
-  params->static_catalog = std::move(manifest_value);
-
 #if defined(OS_WIN) && defined(COMPONENT_BUILD)
   // In Windows component builds, ensure that loaded service binaries always
   // search this exe's dir for DLLs.
   SetDllDirectory(exe_path.value().c_str());
 #endif
 
-  // We want the Context to outlive the MessageLoop so that pipes are all
-  // gracefully closed / error-out before we try to shut the Context down.
-  service_manager::Context service_manager_context;
-  {
-    base::MessageLoop message_loop;
-    base::i18n::InitializeICU();
-    service_manager_context.Init(std::move(params));
+  base::i18n::InitializeICU();
 
-    message_loop.task_runner()->PostTask(
-        FROM_HERE,
-        base::Bind(&service_manager::Context::RunCommandLineApplication,
-                   base::Unretained(&service_manager_context)));
+  mojo::edk::Init();
 
-    base::RunLoop().Run();
+  base::Thread ipc_thread("IPC thread");
+  ipc_thread.StartWithOptions(
+      base::Thread::Options(base::MessageLoop::TYPE_IO, 0));
 
-    // Must be called before |message_loop| is destroyed.
-    service_manager_context.Shutdown();
-  }
+  // We can use fast IPC shutdown here since service manager termination must
+  // effectively bring down all services as well.
+  mojo::edk::ScopedIPCSupport ipc_support(
+      ipc_thread.task_runner(),
+      mojo::edk::ScopedIPCSupport::ShutdownPolicy::FAST);
 
+  base::MessageLoop message_loop;
+  service_manager::Context service_manager_context(nullptr,
+                                                   std::move(manifest_value));
+  message_loop.task_runner()->PostTask(
+      FROM_HERE,
+      base::Bind(&service_manager::Context::RunCommandLineApplication,
+                 base::Unretained(&service_manager_context)));
+  base::RunLoop().Run();
   return 0;
 }