Cascade shutdown of instances

mash/browser_driver/browser_driver_application_delegate.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "mash/browser_driver/browser_driver_application_delegate.h"
 
 #include <stdint.h>
 
 #include "base/bind.h"
+#include "base/message_loop/message_loop.h"
 #include "components/mus/public/cpp/event_matcher.h"
 #include "mojo/shell/public/cpp/connection.h"
 #include "mojo/shell/public/cpp/connector.h"
 
 namespace mash {
 namespace browser_driver {
 namespace {
 
 enum class Accelerator : uint32_t {
   NewWindow,
@@ skipping 15 matching lines @@
     {Accelerator::NewTab, mus::mojom::KeyboardCode::T,
      mus::mojom::kEventFlagControlDown},
     {Accelerator::NewIncognitoWindow, mus::mojom::KeyboardCode::N,
      mus::mojom::kEventFlagControlDown | mus::mojom::kEventFlagShiftDown},
 };
 
 void AssertTrue(bool success) {
   DCHECK(success);
 }
 
+void DoNothing() {}
+
 }  // namespace
 
 BrowserDriverApplicationDelegate::BrowserDriverApplicationDelegate()
     : connector_(nullptr),
-      binding_(this) {}
+      binding_(this),
+      weak_factory_(this) {}
 
 BrowserDriverApplicationDelegate::~BrowserDriverApplicationDelegate() {}
 
 void BrowserDriverApplicationDelegate::Initialize(
     mojo::Connector* connector,
     const mojo::Identity& identity,
     uint32_t id) {
   connector_ = connector;
   AddAccelerators();
 }
 
 bool BrowserDriverApplicationDelegate::AcceptConnection(
     mojo::Connection* connection) {
   return true;
 }
 
+void BrowserDriverApplicationDelegate::ShellConnectionLost() {
+  // Prevent the code in AddAccelerators() from keeping this app alive.
+  binding_.set_connection_error_handler(base::Bind(&DoNothing));
+  base::MessageLoop::current()->QuitWhenIdle();
+}
+
 void BrowserDriverApplicationDelegate::OnAccelerator(
     uint32_t id, mus::mojom::EventPtr event) {
   switch (static_cast<Accelerator>(id)) {
     case Accelerator::NewWindow:
     case Accelerator::NewTab:
     case Accelerator::NewIncognitoWindow:
       connector_->Connect("exe:chrome");
       // TODO(beng): have Chrome export a service that allows it to be driven by
       //             this driver, e.g. to open new tabs, incognito windows, etc.
       break;
     default:
       NOTREACHED();
       break;
   }
 }
 
 void BrowserDriverApplicationDelegate::AddAccelerators() {
   // TODO(beng): find some other way to get the window manager. I don't like
   //             having to specify it by URL because it may differ per display.
   mus::mojom::AcceleratorRegistrarPtr registrar;
   connector_->ConnectToInterface("mojo:desktop_wm", &registrar);
 
   if (binding_.is_bound())
     binding_.Unbind();
   registrar->SetHandler(binding_.CreateInterfacePtrAndBind());
   // If the window manager restarts, the handler pipe will close and we'll need
   // to re-add our accelerators when the window manager comes back up.
   binding_.set_connection_error_handler(
       base::Bind(&BrowserDriverApplicationDelegate::AddAccelerators,
-                 base::Unretained(this)));
+                 weak_factory_.GetWeakPtr()));
 
   for (const AcceleratorSpec& spec : g_spec) {
     registrar->AddAccelerator(
         static_cast<uint32_t>(spec.id),
         mus::CreateKeyMatcher(spec.keyboard_code, spec.event_flags),
         base::Bind(&AssertTrue));
   }
 }
 
 }  // namespace browser_driver
 }  // namespace main