RawChannelPosix: Close handles only if they are sent successfully.

third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc

Index: third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc
diff --git a/third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc b/third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc
index d8c55d56b1b2bb3ef2b3f45c0ed53a60fdbeabe0..c2b2ef0730cee09d952f7461a2e1b55535ef7955 100644
--- a/third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc
+++ b/third_party/mojo/src/mojo/edk/system/raw_channel_posix.cc
@@ -244,8 +244,10 @@ RawChannel::IOResult RawChannelPosix::WriteNoLock(
 
     write_result = embedder::PlatformChannelSendmsgWithHandles(
         fd_.get(), iov, buffer_count, platform_handles, num_platform_handles);
-    for (size_t i = 0; i < num_platform_handles; i++)
-      platform_handles[i].CloseIfNecessary();
+    if (write_result >= 0) {
+      for (size_t i = 0; i < num_platform_handles; i++)
+        platform_handles[i].CloseIfNecessary();
+    }
   } else {
     std::vector<WriteBuffer::Buffer> buffers;
     write_buffer_no_lock()->GetBuffers(&buffers);