Upgrade the windows specific version of LaunchProcess to avoid raw handles.

chrome/browser/extensions/api/messaging/native_message_process_host.cc

Index: chrome/browser/extensions/api/messaging/native_message_process_host.cc
diff --git a/chrome/browser/extensions/api/messaging/native_message_process_host.cc b/chrome/browser/extensions/api/messaging/native_message_process_host.cc
index 98976a103bf4c9c14c3da1eb1ada08c304067f41..c28b233dea7333b39a2e885cab378926a1657e05 100644
--- a/chrome/browser/extensions/api/messaging/native_message_process_host.cc
+++ b/chrome/browser/extensions/api/messaging/native_message_process_host.cc
@@ -47,7 +47,6 @@ NativeMessageProcessHost::NativeMessageProcessHost(
       native_host_name_(native_host_name),
       launcher_(launcher.Pass()),
       closed_(false),
-      process_handle_(base::kNullProcessHandle),
 #if defined(OS_POSIX)
       read_file_(-1),
 #endif
@@ -103,7 +102,7 @@ void NativeMessageProcessHost::LaunchHostProcess() {
 
 void NativeMessageProcessHost::OnHostProcessLaunched(
     NativeProcessLauncher::LaunchResult result,
-    base::ProcessHandle process_handle,
+    base::Process process,
     base::File read_file,
     base::File write_file) {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ -125,7 +124,7 @@ void NativeMessageProcessHost::OnHostProcessLaunched(
       break;
   }
 
-  process_handle_ = process_handle;
+  process_ = process.Pass();
 #if defined(OS_POSIX)
   // This object is not the owner of the file so it should not keep an fd.
   read_file_ = read_file.GetPlatformFile();
@@ -349,17 +348,17 @@ void NativeMessageProcessHost::Close(const std::string& error_message) {
     client_->CloseChannel(error_message);
   }
 
-  if (process_handle_ != base::kNullProcessHandle) {
+  if (process_.IsValid()) {
     // Kill the host process if necessary to make sure we don't leave zombies.
     // On OSX base::EnsureProcessTerminated() may block, so we have to post a
     // task on the blocking pool.
 #if defined(OS_MACOSX)
     content::BrowserThread::PostBlockingPoolTask(
-        FROM_HERE, base::Bind(&base::EnsureProcessTerminated, process_handle_));
+        FROM_HERE,
+        base::Bind(&base::EnsureProcessTerminated, Passed(&process_)));
 #else
-    base::EnsureProcessTerminated(process_handle_);
+    base::EnsureProcessTerminated(process_.Pass());

[gab, 2014/11/27 13:28:44]

Is it possible that this fixes http://crbug.com/436072 ? (i.e., maybe the
process was kept alive simply because there was a leaked handle opened to it
even though the process itself had been terminated? or do terminated processes
really get terminated regardless and opened handles just keep the process info
alive, not the process itself?)

[rvargas (doing something else), 2014/12/01 20:50:36]

A handle should only keep alive the process object (in the kernel) so that the
exit code is retrievable, but all resources required for the process itself
should be released at exit time.

So I don't think that leaks fixed by this CL (as it does) will solve that bug.

 #endif
-    process_handle_ = base::kNullProcessHandle;

[Finnur, 2014/11/27 13:58:26]

Is it possible that this is being nulled to prevent EnsureProcessTerminated
being called twice on Mac if code runs twice? Is that benign perhaps?

[gab, 2014/11/27 14:29:51]

By doing process_.Pass() above, I'd assume |process_| itself becomes invalid,
which provides the same safety guard as before on line 351, no?

[Finnur, 2014/11/27 16:41:59]

Haven't used Pass() all that much, but if that's how it works then that's fine. 

[gab, 2014/11/27 16:47:39]

Process is a move-only type and .Pass() here invokes the move-only constructor
which results in the parameter taking the ScopedHandle from |process_| @ [1] --
and the handle is thus closed the minute the parameter goes out of scope.

[1]
https://code.google.com/p/chromium/codesearch#chromium/src/base/process/proce...

   }
 }