Mojo EDK: Add safe process connection API

chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc

 // Copyright 2016 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 "chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.h"
 
 #include <string>
 #include <utility>
 
 #include "base/location.h"
 #include "base/logging.h"
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/common/video_accelerator.mojom.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/gpu_service_registry.h"
 #include "mojo/edk/embedder/embedder.h"
+#include "mojo/edk/embedder/pending_process_connection.h"
 #include "mojo/edk/embedder/platform_channel_pair.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "services/service_manager/public/cpp/interface_provider.h"
 
 namespace arc {
 
 namespace {
 
 void ConnectToVideoAcceleratorServiceOnIOThread(
     mojom::VideoAcceleratorServiceRequest request) {
@@ skipping 36 matching lines @@
   video_instance->Init(binding_.CreateInterfacePtrAndBind());
 }
 
 void GpuArcVideoServiceHost::OnBootstrapVideoAcceleratorFactory(
     const OnBootstrapVideoAcceleratorFactoryCallback& callback) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   // Hardcode pid 0 since it is unused in mojo.
   const base::ProcessHandle kUnusedChildProcessHandle =
       base::kNullProcessHandle;
+  mojo::edk::PendingProcessConnection process;
   mojo::edk::PlatformChannelPair channel_pair;
-  std::string child_token = mojo::edk::GenerateRandomToken();
-  mojo::edk::ChildProcessLaunched(kUnusedChildProcessHandle,
-                                  channel_pair.PassServerHandle(), child_token);
+  process.Connect(kUnusedChildProcessHandle, channel_pair.PassServerHandle());
 
   MojoHandle wrapped_handle;
   MojoResult wrap_result = mojo::edk::CreatePlatformHandleWrapper(
       channel_pair.PassClientHandle(), &wrapped_handle);
   if (wrap_result != MOJO_RESULT_OK) {
     LOG(ERROR) << "Pipe failed to wrap handles. Closing: " << wrap_result;
     callback.Run(mojo::ScopedHandle(), std::string());
     return;
   }
   mojo::ScopedHandle child_handle{mojo::Handle(wrapped_handle)};
 
-  std::string token = mojo::edk::GenerateRandomToken();
-  mojo::ScopedMessagePipeHandle server_pipe =
-      mojo::edk::CreateParentMessagePipe(token, child_token);
-  if (!server_pipe.is_valid()) {
-    LOG(ERROR) << "Invalid pipe";
-    callback.Run(mojo::ScopedHandle(), std::string());
-    return;
-  }
+  std::string token;
+  mojo::ScopedMessagePipeHandle server_pipe = process.CreateMessagePipe(&token);
   callback.Run(std::move(child_handle), token);
 
   mojo::MakeStrongBinding(base::MakeUnique<VideoAcceleratorFactoryService>(),
                           mojo::MakeRequest<mojom::VideoAcceleratorFactory>(
                               std::move(server_pipe)));
 }
 
 }  // namespace arc