Re-land: "Use a token to initialise ChannelMojo and MojoApplication everywhere."

content/test/render_thread_impl_browser_test_ipc_helper.cc

Index: content/test/render_thread_impl_browser_test_ipc_helper.cc
diff --git a/content/test/render_thread_impl_browser_test_ipc_helper.cc b/content/test/render_thread_impl_browser_test_ipc_helper.cc
index 241ec1ce9e4e70735a81ed98e0217f7a2be6a9e1..11f08516bb27efc80448f70512a4c7ec0d73cf0f 100644
--- a/content/test/render_thread_impl_browser_test_ipc_helper.cc
+++ b/content/test/render_thread_impl_browser_test_ipc_helper.cc
@@ -4,8 +4,8 @@
 
 #include "content/test/render_thread_impl_browser_test_ipc_helper.h"
 
-#include "content/common/mojo/channel_init.h"
 #include "content/public/common/mojo_channel_switches.h"
+#include "mojo/edk/embedder/embedder.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace content {
@@ -48,18 +48,15 @@ void RenderThreadImplBrowserIPCTestHelper::SetupMojo() {
 
   ipc_support_.reset(new IPC::ScopedIPCSupport(ipc_thread_->task_runner()));
   mojo_application_host_.reset(new MojoApplicationHost());
-  mojo_application_host_->OverrideIOTaskRunnerForTest(
-      ipc_thread_->task_runner());
+  mojo_application_token_ = mojo_application_host_->GetToken();
+
+  mojo_ipc_token_ = mojo::edk::GenerateRandomToken();
 
   mojo::MessagePipe pipe;
   channel_ = IPC::ChannelProxy::Create(
-      IPC::ChannelMojo::CreateServerFactory(std::move(pipe.handle0)),
+      IPC::ChannelMojo::CreateServerFactory(
+          mojo::edk::CreateParentMessagePipe(mojo_ipc_token_)),
       dummy_listener_.get(), ipc_thread_->task_runner());
-  message_pipe_handle_ = std::move(pipe.handle1);
-
-  mojo_application_host_->Init();
-  mojo_application_host_->Activate(channel_.get(),
-                                   base::GetCurrentProcessHandle());
 }
 
 scoped_refptr<base::SingleThreadTaskRunner>