Change ChildProcess::set_main_thread registration to occur inside the RenderThreadImpl::Init method.

content/renderer/renderer_main.cc

 // 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/base_switches.h"
 #include "base/command_line.h"
 #include "base/debug/debugger.h"
 #include "base/debug/trace_event.h"
 #include "base/i18n/rtl.h"
 #include "base/memory/ref_counted.h"
@@ skipping 197 matching lines @@
   }
 
   // Load pepper plugins before engaging the sandbox.
   PepperPluginRegistry::GetInstance();
 
   {
 #if defined(OS_WIN) || defined(OS_MACOSX)
     // TODO(markus): Check if it is OK to unconditionally move this
     // instruction down.
     RenderProcessImpl render_process;
-    render_process.set_main_thread(new RenderThreadImpl());
+    // The RenderThreadImpl will register itself as the main thread for the
+    // current process.
+    new RenderThreadImpl();
 #endif
     bool run_loop = true;
     if (!no_sandbox) {
       run_loop = platform.EnableSandbox();
     } else {
       LOG(ERROR) << "Running without renderer sandbox";
     }
 #if defined(OS_POSIX) && !defined(OS_MACOSX)
     RenderProcessImpl render_process;
-    render_process.set_main_thread(new RenderThreadImpl());
+    // The RenderThreadImpl will register itself as the main thread for the
+    // current process.
+    new RenderThreadImpl();
 #endif
 
     platform.RunSandboxTests();
 
     startup_timer.Stop();  // End of Startup Time Measurement.
 
     if (run_loop) {
 #if defined(OS_MACOSX)
       if (pool)
         pool->Recycle();
 #endif
       TRACE_EVENT_BEGIN_ETW("RendererMain.START_MSG_LOOP", 0, 0);
       MessageLoop::current()->Run();
       TRACE_EVENT_END_ETW("RendererMain.START_MSG_LOOP", 0, 0);
     }
   }
   platform.PlatformUninitialize();
   TRACE_EVENT_END_ETW("RendererMain", 0, "");
   return 0;
 }