Embed a mojo ApplicationManager in content/browser

content/browser/mojo_shell_context_impl.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 "content/browser/mojo_shell_context_impl.h"
+
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/memory/weak_ptr.h"
+#include "base/single_thread_task_runner.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/synchronization/lock.h"
+#include "base/thread_task_runner_handle.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/content_browser_client.h"
+#include "content/public/browser/mojo_app_connection.h"
+#include "content/public/browser/utility_process_host.h"
+#include "content/public/browser/utility_process_host_client.h"
+#include "content/public/common/content_client.h"
+#include "content/public/common/process_control.mojom.h"
+#include "content/public/common/service_registry.h"
+#include "content/public/common/static_mojo_application_loader.h"
+#include "mojo/application/public/cpp/application_delegate.h"
+#include "mojo/common/url_type_converters.h"
+#include "mojo/services/network/public/interfaces/url_loader.mojom.h"
+#include "mojo/shell/application_loader.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/interface_request.h"
+#include "third_party/mojo/src/mojo/public/cpp/bindings/string.h"
+
+namespace content {
+
+namespace {
+
+// Virtual app URL to use as the requestor identity when connecting from browser
+// code to a Mojo app via the shell proxy.
+const char kBrowserAppUrl[] = "system:content_browser";
+
+// An ApplicationRegistry instance used for testing to override builtin loaders.
+base::LazyInstance<base::Callback<void(ApplicationRegistry*)>>
+g_application_registry_initializer_for_testing;
+
+void StartProcessOnIOThread(mojo::InterfaceRequest<ProcessControl> request) {
+  UtilityProcessHost* process_host =
+      UtilityProcessHost::Create(nullptr, nullptr);
+  // TODO(rockot): Make it possible for the embedder to associate app URLs with
+  // app names so we can have more meaningful process names here.
+  process_host->SetName(base::UTF8ToUTF16("Mojo Application"));
+  if (process_host->StartMojoMode()) {
+    ServiceRegistry* services = process_host->GetServiceRegistry();
+    services->ConnectToRemoteService(request.Pass());
+  } else {
+    LOG(ERROR) << "Unable to start utility process.";
+  }
+}
+
+void OnApplicationLoaded(
+    const GURL& url, LoadApplicationResult result) {
+  if (result != LOAD_APPLICATION_RESULT_OK) {
+    LOG(ERROR) << "Failed to launch Mojo application for " << url.spec();
+  }
+}
+
+// The default loader to use for all applications. This launches a utility
+// process and forwards the Load request the ProcessControl service there.
+class UtilityProcessLoader : public mojo::shell::ApplicationLoader {
+ public:
+  UtilityProcessLoader() {}
+  ~UtilityProcessLoader() override {}
+
+ private:
+  // mojo::shell::ApplicationLoader:
+  void Load(
+      const GURL& url,
+      mojo::InterfaceRequest<mojo::Application> application_request) override {
+    ProcessControlPtr process_control;
+    auto process_request = mojo::GetProxy(&process_control);
+    BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)
+        ->PostTask(FROM_HERE,
+                   base::Bind(&StartProcessOnIOThread,
+                              base::Passed(&process_request)));
+    process_control->LoadApplication(
+        mojo::String::From(url.spec()), application_request.Pass(),
+        base::Bind(&OnApplicationLoaded, url));
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(UtilityProcessLoader);
+};
+
+}  // namespace
+
+// Thread-safe proxy providing global browser access to the shell context.
+class MojoShellContextImpl::Proxy {
+ public:
+  Proxy() {}
+  ~Proxy() {}
+
+  void Reset(base::WeakPtr<MojoShellContextImpl> weak_shell_context);
+  void ConnectToApplication(
+      const GURL& url,
+      mojo::InterfaceRequest<mojo::ServiceProvider> request);
+
+ private:
+  base::Lock lock_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+  base::WeakPtr<MojoShellContextImpl> weak_shell_context_;
+
+  DISALLOW_COPY_AND_ASSIGN(Proxy);
+};
+
+// static
+base::LazyInstance<MojoShellContextImpl::Proxy> MojoShellContextImpl::proxy_ =
+    LAZY_INSTANCE_INITIALIZER;
+
+void MojoShellContextImpl::Proxy::Reset(
+    base::WeakPtr<MojoShellContextImpl> weak_shell_context) {
+  base::AutoLock locker(lock_);
+  DCHECK(!weak_shell_context_ || !weak_shell_context);
+  weak_shell_context_ = weak_shell_context;
+  if (weak_shell_context_) {
+    task_runner_ = base::ThreadTaskRunnerHandle::Get();
+  } else {
+    task_runner_ = nullptr;
+  }
+}
+
+void MojoShellContextImpl::Proxy::ConnectToApplication(
+    const GURL& url,
+    mojo::InterfaceRequest<mojo::ServiceProvider> request) {
+  base::AutoLock locker(lock_);
+  if (!task_runner_) {
+    LOG(ERROR) << "No shell context available to connect to " << url.spec();
+    return;
+  }
+  if (task_runner_ == base::ThreadTaskRunnerHandle::Get()) {
+    if (weak_shell_context_) {
+      weak_shell_context_->ConnectToApplicationOnOwnThread(
+          url, request.Pass());
+    }
+  } else {
+    task_runner_->PostTask(
+        FROM_HERE,
+        base::Bind(&MojoShellContextImpl::ConnectToApplicationOnOwnThread,
+                   weak_shell_context_, url, base::Passed(&request)));
+  }
+}
+
+// static
+scoped_ptr<MojoShellContext> MojoShellContext::Create() {
+  return scoped_ptr<MojoShellContext>(new MojoShellContextImpl);
+}
+
+void MojoShellContext::SetApplicationRegistryInitializerForTesting(
+    const base::Callback<void(ApplicationRegistry*)>& registry) {
+  g_application_registry_initializer_for_testing.Get() = registry;
+}
+
+MojoShellContextImpl::MojoShellContextImpl()
+    : application_manager_(new mojo::shell::ApplicationManager(this)),
+      weak_factory_(this) {
+  proxy_.Get().Reset(weak_factory_.GetWeakPtr());
+  application_manager_->set_default_loader(
+      scoped_ptr<mojo::shell::ApplicationLoader>(new UtilityProcessLoader));
+  GetContentClient()->browser()->RegisterMojoApplications(this);
+  if (!g_application_registry_initializer_for_testing.Get().is_null())
+    g_application_registry_initializer_for_testing.Get().Run(this);
+}
+
+MojoShellContextImpl::~MojoShellContextImpl() {
+  proxy_.Get().Reset(base::WeakPtr<MojoShellContextImpl>());
+}
+
+// static
+void MojoShellContextImpl::ConnectToApplication(
+    const GURL& url,
+    mojo::InterfaceRequest<mojo::ServiceProvider> request) {
+  proxy_.Get().ConnectToApplication(url, request.Pass());
+}
+
+void MojoShellContextImpl::RegisterStaticAppForURL(
+    const GURL& url,
+    const StaticAppFactory& factory) {
+  application_manager_->SetLoaderForURL(
+      scoped_ptr<mojo::shell::ApplicationLoader>(
+          new StaticMojoApplicationLoader(factory)),
+      url);
+}
+
+void MojoShellContextImpl::ConnectToApplicationOnOwnThread(
+    const GURL& url,
+    mojo::InterfaceRequest<mojo::ServiceProvider> request) {
+  mojo::URLRequestPtr url_request = mojo::URLRequest::New();
+  url_request->url = mojo::String::From(url);
+  application_manager_->ConnectToApplication(
+      url_request.Pass(), GURL(kBrowserAppUrl), request.Pass(),
+      mojo::ServiceProviderPtr(), base::Bind(&base::DoNothing));
+}
+
+GURL MojoShellContextImpl::ResolveMappings(const GURL& url) {
+  return url;
+}
+
+GURL MojoShellContextImpl::ResolveMojoURL(const GURL& url) {
+  return url;
+}
+
+bool MojoShellContextImpl::CreateFetcher(
+    const GURL& url,
+    const mojo::shell::Fetcher::FetchCallback& loader_callback) {
+  return false;
+}
+
+
+}  // namespace content