Allow Thread to initialize COM for Windows consumers who need it

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 15 matching lines @@
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
 #include "base/path_service.h"
 #include "base/platform_file.h"
 #include "base/process_util.h"
 #include "base/rand_util.h"
 #include "base/stl_util.h"
 #include "base/string_util.h"
 #include "base/supports_user_data.h"
 #include "base/sys_info.h"
-#include "base/threading/thread.h"
+#include "base/threading/com_thread.h"
 #include "base/threading/thread_restrictions.h"
 #include "base/tracked_objects.h"
 #include "content/browser/appcache/appcache_dispatcher_host.h"
 #include "content/browser/appcache/chrome_appcache_service.h"
 #include "content/browser/browser_main.h"
 #include "content/browser/browser_main_loop.h"
 #include "content/browser/child_process_security_policy_impl.h"
 #include "content/browser/device_orientation/orientation_message_filter.h"
 #include "content/browser/dom_storage/dom_storage_context_impl.h"
 #include "content/browser/dom_storage/dom_storage_message_filter.h"
@@ skipping 78 matching lines @@
 #include "third_party/skia/include/core/SkBitmap.h"
 
 extern bool g_exited_main_message_loop;
 
 static const char* kSiteProcessMapKeyName = "content_site_process_map";
 
 namespace content {
 
 // This class creates the IO thread for the renderer when running in
 // single-process mode.  It's not used in multi-process mode.
-class RendererMainThread : public base::Thread {
+class RendererMainThread : public base::ComThread {
  public:
   explicit RendererMainThread(const std::string& channel_id)
-      : base::Thread("Chrome_InProcRendererThread"),
+      : ComThread("Chrome_InProcRendererThread", false),
         channel_id_(channel_id) {
   }

[cpu_(ooo_6.6-7.5), 2012/10/04 18:09:03]

I rather not derive from base::Thread, I rather have

#if defined(OS_WIN)
  base::Thread("Chrome_InProcRendererThread", COM_STA),
#else
  base::Thread("Chrome_InProcRendererThread"),
#endif

or some such, for the people that need STA or MTA, if you can get by not
initializing COM in this thread then then the ctor with 1 argument works and you
don't need ifdefs or ComThreads in cross platform code.

 
   virtual ~RendererMainThread() {
     Stop();
   }
 
  protected:
-  virtual void Init() {
-#if defined(OS_WIN)
-    com_initializer_.reset(new base::win::ScopedCOMInitializer());
-#endif
-
+  virtual void Init() OVERRIDE {
+    ComThread::Init();
     render_process_.reset(new RenderProcessImpl());
     new RenderThreadImpl(channel_id_);
   }
 
   virtual void CleanUp() {
     render_process_.reset();
 
-#if defined(OS_WIN)
-    com_initializer_.reset();
-#endif
+    ComThread::CleanUp();
+
     // It's a little lame to manually set this flag.  But the single process
     // RendererThread will receive the WM_QUIT.  We don't need to assert on
     // this thread, so just force the flag manually.
     // If we want to avoid this, we could create the InProcRendererThread
     // directly with _beginthreadex() rather than using the Thread class.
     // We used to set this flag in the Init function above. However there
     // other threads like WebThread which are created by this thread
     // which resets this flag. Please see Thread::StartWithOptions. Setting
     // this flag to true in Cleanup works around these problems.
-    base::Thread::SetThreadWasQuitProperly(true);
+    SetThreadWasQuitProperly(true);
   }
 
  private:
   std::string channel_id_;
-#if defined(OS_WIN)
-  scoped_ptr<base::win::ScopedCOMInitializer> com_initializer_;
-#endif
   scoped_ptr<RenderProcess> render_process_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererMainThread);
 };
 
 namespace {
 
 // Helper class that we pass to ResourceMessageFilter so that it can find the
 // right net::URLRequestContext for a request.
 class RendererURLRequestContextSelector
@@ skipping 1379 matching lines @@
       const gfx::Size& size,
       int32 gpu_process_host_id) {
   TRACE_EVENT0("renderer_host",
                "RenderWidgetHostImpl::OnCompositorSurfaceBuffersSwappedNoHost");
   RenderWidgetHostImpl::AcknowledgeBufferPresent(route_id,
                                                  gpu_process_host_id,
                                                  0);
 }
 
 }  // namespace content