Allow Thread to initialize COM for Windows consumers who need it

base/threading/thread.cc

Index: base/threading/thread.cc
===================================================================
--- base/threading/thread.cc	(revision 162015)
+++ base/threading/thread.cc	(working copy)
@@ -11,6 +11,10 @@
 #include "base/threading/thread_restrictions.h"
 #include "base/synchronization/waitable_event.h"
 
+#if defined(OS_WIN)
+#include "base/win/scoped_com_initializer.h"
+#endif
+
 namespace base {
 
 namespace {
@@ -60,11 +64,20 @@
 }
 
 bool Thread::Start() {
-  return StartWithOptions(Options());
+  Options options;
+#if defined(OS_WIN)
+  if (com_status_ == STA)
+    options.message_loop_type = MessageLoop::TYPE_UI;
+#endif
+  return StartWithOptions(options);
 }
 
 bool Thread::StartWithOptions(const Options& options) {
   DCHECK(!message_loop_);
+#if defined(OS_WIN)
+  DCHECK((com_status_ != STA) ||
+      (options.message_loop_type == MessageLoop::TYPE_UI));
+#endif
 
   SetThreadWasQuitProperly(false);
 
@@ -90,7 +103,7 @@
 }
 
 void Thread::Stop() {
-  if (!thread_was_started())
+  if (!started_)
     return;
 
   StopSoon();
@@ -157,6 +170,14 @@
     message_loop.set_thread_name(name_);
     message_loop_ = &message_loop;
 
+#if defined(OS_WIN)
+    if (com_status_ != NONE) {
+      com_initializer_.reset((com_status_ == STA) ?
+          new win::ScopedCOMInitializer() :
+          new win::ScopedCOMInitializer(win::ScopedCOMInitializer::kMTA));
+    }
+#endif
+
     // Let the thread do extra initialization.
     // Let's do this before signaling we are started.
     Init();
@@ -172,6 +193,10 @@
     // Let the thread do extra cleanup.
     CleanUp();
 
+#if defined(OS_WIN)
+    com_initializer_.reset();

[Ami GONE FROM CHROMIUM, 2012/10/16 02:52:03]

observation: this variable is only used in this function, so it could be a local
instead of class-member (and stack-allocated instead of heap, if it's not big).

This would let you drop the fwd-decl in the .h, too.

+#endif
+
     // Assert that MessageLoop::Quit was called by ThreadQuitHelper.
     DCHECK(GetThreadWasQuitProperly());