Embed a mojo ApplicationManager in content/browser

content/browser/mojo/mojo_shell_context.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/mojo_shell_context.h"
+
+#include "base/lazy_instance.h"
+#include "base/macros.h"
+#include "base/single_thread_task_runner.h"
+#include "base/strings/utf_string_conversions.h"
+#include "base/thread_task_runner_handle.h"
+#include "content/common/process_control.mojom.h"
+#include "content/public/browser/browser_thread.h"
+#include "content/public/browser/content_browser_client.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/service_registry.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 "mojo/shell/static_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 extra set of apps to register on initialization, if set by a test.
+const MojoShellContext::StaticApplicationMap* g_applications_for_test;
+
+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"));
+  process_host->StartMojoMode();
+  ServiceRegistry* services = process_host->GetServiceRegistry();
+  services->ConnectToRemoteService(request.Pass());
+}
+
+void OnApplicationLoaded(const GURL& url, bool success) {
+  if (!success)
+    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::PostTask(
+        BrowserThread::IO, FROM_HERE,
+        base::Bind(&StartProcessOnIOThread, base::Passed(&process_request)));
+    process_control->LoadApplication(url.spec(), application_request.Pass(),
+                                     base::Bind(&OnApplicationLoaded, url));
+  }
+
+  DISALLOW_COPY_AND_ASSIGN(UtilityProcessLoader);
+};
+
+}  // namespace
+
+// Thread-safe proxy providing access to the shell context from any thread.
+class MojoShellContext::Proxy {
+ public:
+  Proxy(MojoShellContext* shell_context)
+      : shell_context_(shell_context),
+        task_runner_(base::ThreadTaskRunnerHandle::Get()) {}
+
+  ~Proxy() {}
+
+  void ConnectToApplication(
+      const GURL& url,
+      mojo::InterfaceRequest<mojo::ServiceProvider> request) {
+    if (task_runner_ == base::ThreadTaskRunnerHandle::Get()) {
+      if (shell_context_)
+        shell_context_->ConnectToApplicationOnOwnThread(url, request.Pass());
+    } else {
+      // |shell_context_| outlives the main MessageLoop, so it's safe for it to
+      // be unretained here.
+      task_runner_->PostTask(
+          FROM_HERE,
+          base::Bind(&MojoShellContext::ConnectToApplicationOnOwnThread,
+                     base::Unretained(shell_context_), url,
+                     base::Passed(&request)));
+    }
+  }
+
+ private:
+  MojoShellContext* shell_context_;
+  scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
+
+  DISALLOW_COPY_AND_ASSIGN(Proxy);
+};
+
+// static
+base::LazyInstance<scoped_ptr<MojoShellContext::Proxy>>
+    MojoShellContext::proxy_ = LAZY_INSTANCE_INITIALIZER;
+
+void MojoShellContext::SetApplicationsForTest(
+    const StaticApplicationMap* apps) {
+  g_applications_for_test = apps;
+}
+
+MojoShellContext::MojoShellContext()
+    : application_manager_(new mojo::shell::ApplicationManager(this)) {
+  proxy_.Get().reset(new Proxy(this));
+  application_manager_->set_default_loader(
+      scoped_ptr<mojo::shell::ApplicationLoader>(new UtilityProcessLoader));
+
+  StaticApplicationMap apps;
+  GetContentClient()->browser()->RegisterMojoApplications(&apps);
+  if (g_applications_for_test) {
+    // Add testing apps to the map, potentially overwriting whatever the
+    // browser client registered.
+    for (const auto& entry : *g_applications_for_test)
+      apps[entry.first] = entry.second;
+  }
+  for (const auto& entry : apps) {
+    application_manager_->SetLoaderForURL(
+        scoped_ptr<mojo::shell::ApplicationLoader>(
+            new mojo::shell::StaticApplicationLoader(entry.second)),
+        entry.first);
+  }
+}
+
+MojoShellContext::~MojoShellContext() {
+}
+
+// static
+void MojoShellContext::ConnectToApplication(
+    const GURL& url,
+    mojo::InterfaceRequest<mojo::ServiceProvider> request) {
+  proxy_.Get()->ConnectToApplication(url, request.Pass());
+}
+
+void MojoShellContext::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 MojoShellContext::ResolveMappings(const GURL& url) {
+  return url;
+}
+
+GURL MojoShellContext::ResolveMojoURL(const GURL& url) {
+  return url;
+}
+
+bool MojoShellContext::CreateFetcher(
+    const GURL& url,
+    const mojo::shell::Fetcher::FetchCallback& loader_callback) {
+  return false;
+}
+
+}  // namespace content