Fix double-initialization of CComModule.

base/win/atl_module.cc

Index: base/win/atl_module.cc
===================================================================
--- base/win/atl_module.cc	(revision 0)
+++ base/win/atl_module.cc	(revision 0)
@@ -0,0 +1,21 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/win/atl_module.h"
+
+#include <atlbase.h>
+#include <atlcom.h>
+
+namespace base {
+namespace win {
+
+void CreateATLModuleIfNeeded() {
+  if (_pAtlModule == NULL) {
+    static CComModule module;

[rvargas (doing something else), 2011/11/04 21:53:03]

Shouldn't this should be CAtlModule? The constructor would initialize
_pAtlModule internally.

However, this whole thing will just initialize ATL for base.dll, and we
certainly don't need that.

[dmazzoni, 2011/11/04 22:34:47]

Is there any other good reason? Otherwise it just looks like magic to anyone who
doesn't know CAtlModule. I think it's more clear to see the line of code setting
_pAtlModule to &module, it makes it obvious to anyone new searching through the
code where this happens.
Oops, you're totally right about that. Fixed, take another look.

[rvargas (doing something else), 2011/11/04 22:52:14]

It should feel like black magic already: what is _pAtlModule and why do we care
about it?

My point was that there is more initialization that we need than just setting
this pointer, and all relevant stuff happens inside the constructor of the
object (including setting the global), and we are overwriting a value that is
internal to ATL. In fact, creating a CComModule initializes not only _pAtlModule
but also _pModule (which is probably a good thing, so ignore my comment about
changing the type).

So I think it is better just to leave the constructor do its thing and add a
comment for the curious.

[dmazzoni, 2011/11/04 23:01:30]

Didn't realize it initialized it. Fixed.

+    _pAtlModule = &module;
+  }
+}
+
+}  // namespace win
+}  // namespace base