Move content's shell connections to the IO thread

content/browser/mojo/mojo_child_connection.cc

Index: content/browser/mojo/mojo_child_connection.cc
diff --git a/content/browser/mojo/mojo_child_connection.cc b/content/browser/mojo/mojo_child_connection.cc
index cb7ea98565307eeacde7f58a9dda8425a2592ecc..1fe0c2e0991c57ba8e0a8b87ac72d08377a4256a 100644
--- a/content/browser/mojo/mojo_child_connection.cc
+++ b/content/browser/mojo/mojo_child_connection.cc
@@ -7,6 +7,7 @@
 #include <stdint.h>
 #include <utility>
 
+#include "base/macros.h"
 #include "content/public/common/mojo_shell_connection.h"
 #include "mojo/edk/embedder/embedder.h"
 #include "mojo/public/cpp/system/message_pipe.h"
@@ -16,43 +17,163 @@
 
 namespace content {
 
-MojoChildConnection::MojoChildConnection(const std::string& application_name,
-                                         const std::string& instance_id,
-                                         const std::string& child_token,
-                                         shell::Connector* connector)
-    : service_token_(mojo::edk::GenerateRandomToken()) {
-  mojo::ScopedMessagePipeHandle service_pipe =
-      mojo::edk::CreateParentMessagePipe(service_token_, child_token);
+namespace {
+
+void CallBinderOnTaskRunner(
+    const shell::InterfaceRegistry::Binder& binder,
+    scoped_refptr<base::SequencedTaskRunner> task_runner,
+    const mojo::String& interface_name,
+    mojo::ScopedMessagePipeHandle request_handle) {
+  task_runner->PostTask(
+      FROM_HERE,
+      base::Bind(binder, interface_name, base::Passed(&request_handle)));
+}
+
+}  // namespace
+
+class MojoChildConnection::IOThreadContext
+    : public base::RefCountedThreadSafe<IOThreadContext> {
+ public:
+  IOThreadContext() {}
+
+  void Initialize(const std::string& application_name,
+                  const std::string& instance_id,
+                  shell::Connector* connector,
+                  mojo::ScopedMessagePipeHandle service_pipe,
+                  scoped_refptr<base::SequencedTaskRunner> io_task_runner,
+                  const shell::InterfaceRegistry::Binder& default_binder) {
+    DCHECK(!io_task_runner_);
+    io_task_runner_ = io_task_runner;
+    std::unique_ptr<shell::Connector> io_thread_connector;
+    if (connector)
+      io_thread_connector = connector->Clone();
+    io_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&IOThreadContext::InitializeOnIOThread, this,
+                   application_name, instance_id,
+                   base::Passed(&io_thread_connector),
+                   base::Passed(&service_pipe),
+                   base::Bind(&CallBinderOnTaskRunner, default_binder,
+                              base::ThreadTaskRunnerHandle::Get())));
+  }
+
+  void ShutDown() {
+    if (!io_task_runner_)
+      return;
+    bool posted = io_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&IOThreadContext::ShutDownOnIOThread, this));
+    DCHECK(posted);
+  }
+
+  void GetRemoteInterfaceOnIOThread(
+      const mojo::String& interface_name,
+      mojo::ScopedMessagePipeHandle request_handle) {
+    if (connection_) {
+      connection_->GetRemoteInterfaces()->GetInterface(
+          interface_name, std::move(request_handle));
+    }
+  }
+
+  void SetProcessHandle(base::ProcessHandle handle) {
+    DCHECK(io_task_runner_);
+    io_task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&IOThreadContext::SetProcessHandleOnIOThread, this, handle));
+  }
+
+ private:
+  friend class base::RefCountedThreadSafe<IOThreadContext>;
+
+  virtual ~IOThreadContext() {}
 
-  shell::mojom::ServicePtr service;
-  service.Bind(mojo::InterfacePtrInfo<shell::mojom::Service>(
-      std::move(service_pipe), 0u));
-  shell::mojom::PIDReceiverRequest pid_receiver_request =
-      GetProxy(&pid_receiver_);
+  void InitializeOnIOThread(
+      const std::string& application_name,
+      const std::string& instance_id,
+      std::unique_ptr<shell::Connector> connector,
+      mojo::ScopedMessagePipeHandle service_pipe,
+      const shell::InterfaceRegistry::Binder& default_binder) {
+    shell::mojom::ServicePtr service;
+    service.Bind(mojo::InterfacePtrInfo<shell::mojom::Service>(
+        std::move(service_pipe), 0u));
+    shell::mojom::PIDReceiverRequest pid_receiver_request =
+        mojo::GetProxy(&pid_receiver_);
 
-  shell::Identity target(application_name, shell::mojom::kInheritUserID,
-                         instance_id);
-  shell::Connector::ConnectParams params(target);
-  params.set_client_process_connection(std::move(service),
-                                       std::move(pid_receiver_request));
+    shell::Identity target(application_name, shell::mojom::kInheritUserID,
+                           instance_id);
+    shell::Connector::ConnectParams params(target);
+    params.set_client_process_connection(std::move(service),
+                                         std::move(pid_receiver_request));
 
-  // In some unit testing scenarios a null connector is passed.
-  if (!connector)
-    return;
+    // In some unit testing scenarios a null connector is passed.
+    if (!connector)
+      return;
+
+    connection_ = connector->Connect(&params);
+    connection_->GetInterfaceRegistry()->set_default_binder(default_binder);
+  }
+
+  void ShutDownOnIOThread() {
+    connection_.reset();
+    pid_receiver_.reset();
+  }
+
+  void SetProcessHandleOnIOThread(base::ProcessHandle handle) {
+    DCHECK(pid_receiver_.is_bound());
+    pid_receiver_->SetPID(base::GetProcId(handle));
+    pid_receiver_.reset();
+  }
+
+  scoped_refptr<base::SequencedTaskRunner> io_task_runner_;
+  std::unique_ptr<shell::Connection> connection_;
+  shell::mojom::PIDReceiverPtr pid_receiver_;
+
+  DISALLOW_COPY_AND_ASSIGN(IOThreadContext);
+};
+
+MojoChildConnection::MojoChildConnection(
+    const std::string& application_name,
+    const std::string& instance_id,
+    const std::string& child_token,
+    shell::Connector* connector,
+    scoped_refptr<base::SequencedTaskRunner> io_task_runner)
+    : context_(new IOThreadContext),
+      service_token_(mojo::edk::GenerateRandomToken()),
+      interface_registry_(nullptr),
+      weak_factory_(this) {
+  mojo::ScopedMessagePipeHandle service_pipe =
+      mojo::edk::CreateParentMessagePipe(service_token_, child_token);
+
+  context_ = new IOThreadContext;
+  context_->Initialize(
+      application_name, instance_id, connector, std::move(service_pipe),
+      io_task_runner,
+      base::Bind(&MojoChildConnection::GetInterface,
+                 weak_factory_.GetWeakPtr()));
+  remote_interfaces_.Forward(
+      base::Bind(&CallBinderOnTaskRunner,
+                 base::Bind(&IOThreadContext::GetRemoteInterfaceOnIOThread,
+                            context_), io_task_runner));
 
-  connection_ = connector->Connect(&params);
 #if defined(OS_ANDROID)
-  service_registry_android_ = ServiceRegistryAndroid::Create(
-      connection_->GetInterfaceRegistry(), connection_->GetRemoteInterfaces());
+  service_registry_android_ =
+      ServiceRegistryAndroid::Create(&interface_registry_, &remote_interfaces_);
 #endif
 }
 
-MojoChildConnection::~MojoChildConnection() {}
+MojoChildConnection::~MojoChildConnection() {
+  context_->ShutDown();
+}
 
 void MojoChildConnection::SetProcessHandle(base::ProcessHandle handle) {
-  DCHECK(pid_receiver_.is_bound());
-  pid_receiver_->SetPID(base::GetProcId(handle));
-  pid_receiver_.reset();
+  context_->SetProcessHandle(handle);
+}
+
+void MojoChildConnection::GetInterface(
+    const mojo::String& interface_name,
+    mojo::ScopedMessagePipeHandle request_handle) {
+  static_cast<shell::mojom::InterfaceProvider*>(&interface_registry_)
+      ->GetInterface(interface_name, std::move(request_handle));
 }
 
 }  // namespace content