Add a guard in MojoBootstrap::OnClientLaunched()

There is a race where the IO thread got error after the UI thread
launched a process. This CL rejects such a case.
This is OK as the error is eventually notified to the UI thread.

TEST=chromeos browser_tests with ChannelMojo being on.
R=viettrungluu@chromium.org
BUG=377980

Review URL: https://codereview.chromium.org/671513011

Cr-Commit-Position: refs/heads/master@{#300589}

2 files changed, 8 insertions, 0 deletions

diff --git a/ipc/mojo/ipc_mojo_bootstrap.cc b/ipc/mojo/ipc_mojo_bootstrap.cc
index 7233de0..30c33a8 100644
--- a/ipc/mojo/ipc_mojo_bootstrap.cc
+++ b/ipc/mojo/ipc_mojo_bootstrap.cc
@@ -84,6 +84,9 @@ void MojoServerBootstrap::SendClientPipeIfReady() {
 }
 
 void MojoServerBootstrap::OnClientLaunched(base::ProcessHandle process) {
+  if (HasFailed())
+    return;
+
   DCHECK_EQ(state(), STATE_INITIALIZED);
   DCHECK_NE(process, base::kNullProcessHandle);
   client_process_ = process;
@@ -202,6 +205,10 @@ void MojoBootstrap::Fail() {
   delegate()->OnBootstrapError();
 }
 
+bool MojoBootstrap::HasFailed() const {
+  return state() == STATE_ERROR;
+}
+
 bool MojoBootstrap::Send(Message* message) {
   return channel_->Send(message);
 }
diff --git a/ipc/mojo/ipc_mojo_bootstrap.h b/ipc/mojo/ipc_mojo_bootstrap.h
index 540becf..5f16ef4 100644
--- a/ipc/mojo/ipc_mojo_bootstrap.h
+++ b/ipc/mojo/ipc_mojo_bootstrap.h
@@ -60,6 +60,7 @@ class IPC_MOJO_EXPORT MojoBootstrap : public Listener {
   Delegate* delegate() const { return delegate_; }
   bool Send(Message* message);
   void Fail();
+  bool HasFailed() const;
 
   State state() const { return state_; }
   void set_state(State state) { state_ = state; }