NaCl: Fix a file descriptor leak on Unix

Before this change, the renderer process leaks a file descriptor every
time a PNaCl translator process is launched or a (P)NaCl process runs
without calling the ppapi_start() API.

There was no leak on Windows, because client-side IPC::ChannelHandles
fill out the "name" field rather than the "pipe.handle" field.

BUG=302078
TEST=Run an invalid pexe repeatedly and manually inspect /proc/PID/fd
  of the renderer process.

Review URL: https://codereview.chromium.org/1473513005

Cr-Commit-Position: refs/heads/master@{#362440}

1 files changed, 15 insertions, 0 deletions

diff --git a/components/nacl/renderer/ppb_nacl_private_impl.cc b/components/nacl/renderer/ppb_nacl_private_impl.cc
index dfc7af8..07d20e2 100644
--- a/components/nacl/renderer/ppb_nacl_private_impl.cc
+++ b/components/nacl/renderer/ppb_nacl_private_impl.cc
@@ -66,6 +66,10 @@
 #include "third_party/WebKit/public/web/WebSecurityOrigin.h"
 #include "third_party/WebKit/public/web/WebURLLoaderOptions.h"
 
+#if defined(OS_WIN)
+#include "base/win/scoped_handle.h"
+#endif
+
 namespace nacl {
 namespace {
 
@@ -121,6 +125,17 @@ class NaClPluginInstance {
  public:
   NaClPluginInstance(PP_Instance instance):
       nexe_load_manager(instance), pexe_size(0) {}
+  ~NaClPluginInstance() {
+    // Make sure that we do not leak a file descriptor if the NaCl loader
+    // process never called ppapi_start() to initialize PPAPI.
+    if (instance_info) {
+#if defined(OS_WIN)
+      base::win::ScopedHandle closer(instance_info->channel_handle.pipe.handle);
+#else
+      base::ScopedFD closer(instance_info->channel_handle.socket.fd);
+#endif
+    }
+  }
 
   NexeLoadManager nexe_load_manager;
   scoped_ptr<JsonManifest> json_manifest;