Improve process launch handle sharing API.

chrome/test/base/mojo_test_connector.cc

Index: chrome/test/base/mojo_test_connector.cc
diff --git a/chrome/test/base/mojo_test_connector.cc b/chrome/test/base/mojo_test_connector.cc
index e76c27071fb0a8e81d1b1509e9f7a53c51934348..32d145910113e829f81f4719d8cf486cea3d9693 100644
--- a/chrome/test/base/mojo_test_connector.cc
+++ b/chrome/test/base/mojo_test_connector.cc
@@ -56,16 +56,12 @@ class MojoTestState : public content::TestState {
     command_line->AppendSwitch(MojoTestConnector::kTestSwitch);
     command_line->AppendSwitchASCII(switches::kMusConfig, mus_config_switch);
 
-    platform_channel_->PrepareToPassClientHandleToChildProcess(
-        command_line, &handle_passing_info_);
 #if defined(OS_WIN)
-    test_launch_options->inherit_handles = true;
-    test_launch_options->handles_to_inherit = &handle_passing_info_;
-#if defined(OFFICIAL_BUILD)
-    CHECK(false) << "Launching mojo process with inherit_handles is insecure!";
-#endif
+    platform_channel_->PrepareToPassClientHandleToChildProcess(
+        command_line, &test_launch_options->handles_to_inherit);
 #elif defined(OS_POSIX)
-    test_launch_options->fds_to_remap = &handle_passing_info_;
+    platform_channel_->PrepareToPassClientHandleToChildProcess(
+        command_line, &test_launch_options->fds_to_remap);
 #else
 #error "Unsupported"
 #endif
@@ -130,10 +126,6 @@ class MojoTestState : public content::TestState {
   // which point |background_service_manager_| takes over ownership.
   service_manager::mojom::ServicePtr service_;
 
-  // NOTE: HandlePassingInformation must remain valid through process launch,
-  // hence it lives here instead of within Init()'s stack.
-  mojo::edk::HandlePassingInformation handle_passing_info_;
-
   std::unique_ptr<mojo::edk::PlatformChannelPair> platform_channel_;
   service_manager::mojom::PIDReceiverPtr pid_receiver_;
   const scoped_refptr<base::TaskRunner> main_task_runner_;