Add more CHECK in GPU and NPAPI process on invalid file descriptors

content/common/np_channel_base.cc

Index: content/common/np_channel_base.cc
diff --git a/content/common/np_channel_base.cc b/content/common/np_channel_base.cc
index 94d78340f7c09e7ea5cb13a0b36ce1ead171e349..d83029534b03d5a04d405ee14af0aa4aab32534e 100644
--- a/content/common/np_channel_base.cc
+++ b/content/common/np_channel_base.cc
@@ -131,6 +131,14 @@ bool NPChannelBase::Init(base::MessageLoopProxy* ipc_message_loop,
   channel_.reset(new IPC::SyncChannel(
       channel_handle_, mode_, this, ipc_message_loop, create_pipe_now,
       shutdown_event));
+
+#if defined(OS_POSIX)
+  // Check the validity of fd for bug investigation.  Remove after fixed.
+  // See for details: crbug.com/95129, crbug.com/97285.
+  if (mode_ == IPC::Channel::MODE_SERVER)
+    CHECK_NE(-1, channel_->GetClientFileDescriptor());
+#endif
+
   channel_valid_ = true;
   return true;
 }