Mojo EDK: Add safe process connection API

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

Index: chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc
diff --git a/chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc b/chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc
index b6799d493a17b4ecb1008f577cb3d12a647d18be..203765d743fba65c9bcc75a4e4298196c56c5120 100644
--- a/chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc
+++ b/chrome/browser/chromeos/arc/video/gpu_arc_video_service_host.cc
@@ -17,6 +17,7 @@
 #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"
@@ -73,10 +74,9 @@ void GpuArcVideoServiceHost::OnBootstrapVideoAcceleratorFactory(
   // 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(
@@ -88,14 +88,8 @@ void GpuArcVideoServiceHost::OnBootstrapVideoAcceleratorFactory(
   }
   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>(),