Revert of Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used (patchset #2 id:20001 of https://codereview.chromium.org/1819063002/ )

Reason for revert:
Looks like to made the mojo_apptests go red. I think this is also making MUS tests fail?

https://build.chromium.org/p/chromium.linux/builders/Linux%20Tests/builds/39128

Original issue's description:
> Quit the message loop by default in ShellConnectionLost when ApplicationRunner is used
>
> This was originally at https://codereview.chromium.org/1814223002/ , but Ben is out and
> I need this for tests, so I'm taking over.
>
> BUG=none
> TEST=covered by tests
> TBR=ben@chromium.org
> R=ben@chromium.org
>
> Committed: https://crrev.com/a50f9840749052fbdec087a304548217cc6fd00b
> Cr-Commit-Position: refs/heads/master@{#382389}

TBR=ben@chromium.org,sky@chromium.org
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=none

Review URL: https://codereview.chromium.org/1821913002

Cr-Commit-Position: refs/heads/master@{#382460}

15 files changed, 34 insertions, 34 deletions

diff --git a/mojo/services/network/network_service_delegate.cc b/mojo/services/network/network_service_delegate.cc
index b257331..1970928 100644
--- a/mojo/services/network/network_service_delegate.cc
+++ b/mojo/services/network/network_service_delegate.cc
@@ -78,6 +78,10 @@ bool NetworkServiceDelegate::AcceptConnection(Connection* connection) {
   return true;
 }
 
+void NetworkServiceDelegate::ShellConnectionLost() {
+  base::MessageLoop::current()->QuitWhenIdle();
+}
+
 void NetworkServiceDelegate::Create(Connection* connection,
                                     InterfaceRequest<NetworkService> request) {
   new NetworkServiceImpl(ref_factory_.CreateRef(), std::move(request));
diff --git a/mojo/services/network/network_service_delegate.h b/mojo/services/network/network_service_delegate.h
index 7098939..8997097 100644
--- a/mojo/services/network/network_service_delegate.h
+++ b/mojo/services/network/network_service_delegate.h
@@ -38,6 +38,7 @@ class NetworkServiceDelegate : public ShellClient,
   void Initialize(Connector* connector, const Identity& identity,
                   uint32_t id) override;
   bool AcceptConnection(Connection* connection) override;
+  void ShellConnectionLost() override;
 
   // InterfaceFactory<NetworkService> implementation.
   void Create(Connection* connection,
diff --git a/mojo/services/tracing/tracing_app.cc b/mojo/services/tracing/tracing_app.cc
index d921a6d..65b4421 100644
--- a/mojo/services/tracing/tracing_app.cc
+++ b/mojo/services/tracing/tracing_app.cc
@@ -42,12 +42,8 @@ bool TracingApp::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
-bool TracingApp::ShellConnectionLost() {
-  // TODO(beng): This is only required because TracingApp isn't run by
-  // ApplicationRunner - instead it's launched automatically by the standalone
-  // shell. It shouldn't be.
+void TracingApp::ShellConnectionLost() {
   base::MessageLoop::current()->QuitWhenIdle();
-  return false;
 }
 
 void TracingApp::Create(mojo::Connection* connection,
diff --git a/mojo/services/tracing/tracing_app.h b/mojo/services/tracing/tracing_app.h
index eb5934a..17f4132 100644
--- a/mojo/services/tracing/tracing_app.h
+++ b/mojo/services/tracing/tracing_app.h
@@ -34,7 +34,7 @@ class TracingApp
  private:
   // mojo::ShellClient implementation.
   bool AcceptConnection(mojo::Connection* connection) override;
-  bool ShellConnectionLost() override;
+  void ShellConnectionLost() override;
 
   // mojo::InterfaceFactory<TraceCollector> implementation.
   void Create(mojo::Connection* connection,
diff --git a/mojo/shell/background/tests/test_service.cc b/mojo/shell/background/tests/test_service.cc
index e69640d..d030a81 100644
--- a/mojo/shell/background/tests/test_service.cc
+++ b/mojo/shell/background/tests/test_service.cc
@@ -25,8 +25,8 @@ class TestClient : public ShellClient,
     connection->AddInterface(this);
     return true;
   }
-  bool ShellConnectionLost() override {
-    return true;
+  void ShellConnectionLost() override {
+    base::MessageLoop::current()->QuitWhenIdle();
   }
 
   // InterfaceFactory<mojom::TestService>:
diff --git a/mojo/shell/public/cpp/lib/application_runner.cc b/mojo/shell/public/cpp/lib/application_runner.cc
index 201aa62..5253053 100644
--- a/mojo/shell/public/cpp/lib/application_runner.cc
+++ b/mojo/shell/public/cpp/lib/application_runner.cc
@@ -5,12 +5,10 @@
 #include "mojo/shell/public/cpp/application_runner.h"
 
 #include "base/at_exit.h"
-#include "base/bind.h"
 #include "base/command_line.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/message_loop/message_loop.h"
 #include "base/process/launch.h"
-#include "base/run_loop.h"
 #include "mojo/shell/public/cpp/shell_client.h"
 #include "mojo/shell/public/cpp/shell_connection.h"
 
@@ -56,9 +54,7 @@ MojoResult ApplicationRunner::Run(MojoHandle shell_client_request_handle,
         client_.get(),
         MakeRequest<shell::mojom::ShellClient>(MakeScopedHandle(
             MessagePipeHandle(shell_client_request_handle)))));
-    base::RunLoop run_loop;
-    connection_->set_connection_lost_closure(run_loop.QuitClosure());
-    run_loop.Run();
+    loop->Run();
     // It's very common for the client to cache the app and terminate on errors.
     // If we don't delete the client before the app we run the risk of the
     // client having a stale reference to the app and trying to use it.
diff --git a/mojo/shell/public/cpp/lib/shell_client.cc b/mojo/shell/public/cpp/lib/shell_client.cc
index 3ca8cd7..c41999b 100644
--- a/mojo/shell/public/cpp/lib/shell_client.cc
+++ b/mojo/shell/public/cpp/lib/shell_client.cc
@@ -17,6 +17,6 @@ bool ShellClient::AcceptConnection(Connection* connection) {
   return false;
 }
 
-bool ShellClient::ShellConnectionLost() { return true; }
+void ShellClient::ShellConnectionLost() {}
 
 }  // namespace mojo
diff --git a/mojo/shell/public/cpp/lib/shell_connection.cc b/mojo/shell/public/cpp/lib/shell_connection.cc
index 62ae598..d1cba7e 100644
--- a/mojo/shell/public/cpp/lib/shell_connection.cc
+++ b/mojo/shell/public/cpp/lib/shell_connection.cc
@@ -86,8 +86,7 @@ void ShellConnection::OnConnectionError() {
   // Note that the ShellClient doesn't technically have to quit now, it may live
   // on to service existing connections. All existing Connectors however are
   // invalid.
-  if (client_->ShellConnectionLost() && !connection_lost_closure_.is_null())
-    connection_lost_closure_.Run();
+  client_->ShellConnectionLost();
   // We don't reset the connector as clients may have taken a raw pointer to it.
   // Connect() will return nullptr if they try to connect to anything.
 }
diff --git a/mojo/shell/public/cpp/shell_client.h b/mojo/shell/public/cpp/shell_client.h
index aff1aac..d6fca12 100644
--- a/mojo/shell/public/cpp/shell_client.h
+++ b/mojo/shell/public/cpp/shell_client.h
@@ -43,13 +43,8 @@ class ShellClient {
 
   // Called when ShellConnection's ShellClient binding (i.e. the pipe the
   // Mojo Shell has to talk to us over) is closed. A shell client may use this
-  // as a signal to terminate. Return true from this method to tell the
-  // ShellConnection to run its connection lost closure if it has one, false to
-  // prevent it from being run. The default implementation returns true.
-  // When used in conjunction with ApplicationRunner, returning true here quits
-  // the message loop created by ApplicationRunner, which results in the app
-  // quitting.
-  virtual bool ShellConnectionLost();
+  // as a signal to terminate.
+  virtual void ShellConnectionLost();
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ShellClient);
diff --git a/mojo/shell/public/cpp/shell_connection.h b/mojo/shell/public/cpp/shell_connection.h
index 3e00cd3..a05f6f1 100644
--- a/mojo/shell/public/cpp/shell_connection.h
+++ b/mojo/shell/public/cpp/shell_connection.h
@@ -61,12 +61,7 @@ class ShellConnection : public shell::mojom::ShellClient {
   // TODO(rockot): Remove this once we get rid of app tests.
   void SetAppTestConnectorForTesting(shell::mojom::ConnectorPtr connector);
 
-  // Specify a function to be called when the connection to the shell is lost.
-  void set_connection_lost_closure(const base::Closure& closure) {
-    connection_lost_closure_ = closure;
-  }
-
-private:
+ private:
   // shell::mojom::ShellClient:
   void Initialize(shell::mojom::IdentityPtr identity,
                   uint32_t id,
@@ -95,8 +90,6 @@ private:
   Binding<shell::mojom::ShellClient> binding_;
   scoped_ptr<Connector> connector_;
 
-  base::Closure connection_lost_closure_;
-
   DISALLOW_COPY_AND_ASSIGN(ShellConnection);
 };
 
diff --git a/mojo/shell/tests/connect/connect_test_app.cc b/mojo/shell/tests/connect/connect_test_app.cc
index 4180763..342e14d 100644
--- a/mojo/shell/tests/connect/connect_test_app.cc
+++ b/mojo/shell/tests/connect/connect_test_app.cc
@@ -79,6 +79,12 @@ class ConnectTestApp : public ShellClient,
 
     return true;
   }
+  void ShellConnectionLost() override {
+    if (base::MessageLoop::current() &&
+        base::MessageLoop::current()->is_running()) {
+      base::MessageLoop::current()->QuitWhenIdle();
+    }
+  }
 
   // InterfaceFactory<test::mojom::ConnectTestService>:
   void Create(Connection* connection,
diff --git a/mojo/shell/tests/connect/connect_test_driver.cc b/mojo/shell/tests/connect/connect_test_driver.cc
index b1bdce4..ace64df 100644
--- a/mojo/shell/tests/connect/connect_test_driver.cc
+++ b/mojo/shell/tests/connect/connect_test_driver.cc
@@ -37,9 +37,8 @@ class Driver : public mojo::ShellClient,
     connection->AddInterface<ClientProcessTest>(this);
     return true;
   }
-  bool ShellConnectionLost() override {
-    // TODO(rockot): http://crbug.com/596621. Should be able to remove this
-    // override entirely.
+  void ShellConnectionLost() override {
+    // TODO: This should exit cleanly.
     _exit(1);
   }
 
diff --git a/mojo/shell/tests/connect/connect_test_package.cc b/mojo/shell/tests/connect/connect_test_package.cc
index 1458e65..c5a1a07 100644
--- a/mojo/shell/tests/connect/connect_test_package.cc
+++ b/mojo/shell/tests/connect/connect_test_package.cc
@@ -184,6 +184,12 @@ class ConnectTestShellClient
     connection->AddInterface<test::mojom::ConnectTestService>(this);
     return true;
   }
+  void ShellConnectionLost() override {
+    if (base::MessageLoop::current() &&
+        base::MessageLoop::current()->is_running()) {
+      base::MessageLoop::current()->QuitWhenIdle();
+    }
+  }
 
   // InterfaceFactory<mojom::ShellClientFactory>:
   void Create(Connection* connection,
diff --git a/mojo/shell/tests/lifecycle/app_client.cc b/mojo/shell/tests/lifecycle/app_client.cc
index 657d967..a2400ec 100644
--- a/mojo/shell/tests/lifecycle/app_client.cc
+++ b/mojo/shell/tests/lifecycle/app_client.cc
@@ -20,6 +20,10 @@ bool AppClient::AcceptConnection(mojo::Connection* connection) {
   return true;
 }
 
+void AppClient::ShellConnectionLost() {
+  GracefulQuit();
+}
+
 void AppClient::Create(mojo::Connection* connection,
                        LifecycleControlRequest request) {
   bindings_.AddBinding(this, std::move(request));
diff --git a/mojo/shell/tests/lifecycle/app_client.h b/mojo/shell/tests/lifecycle/app_client.h
index 5a7d5e6..d389f20 100644
--- a/mojo/shell/tests/lifecycle/app_client.h
+++ b/mojo/shell/tests/lifecycle/app_client.h
@@ -37,6 +37,7 @@ class AppClient : public ShellClient,
 
   // ShellClient:
   bool AcceptConnection(Connection* connection) override;
+  void ShellConnectionLost() override;
 
   // InterfaceFactory<LifecycleControl>:
   void Create(Connection* connection, LifecycleControlRequest request) override;