ccameron's https://codereview.chromium.org/23191007 with some changes to work

content/gpu/gpu_main.cc

Index: content/gpu/gpu_main.cc
diff --git a/content/gpu/gpu_main.cc b/content/gpu/gpu_main.cc
index eeaa11b08c1cac214c37a6cb7c5a6bd02f216a54..baed5ce87bbbf533b11d9c3dc6432bf6d0dae4fc 100644
--- a/content/gpu/gpu_main.cc
+++ b/content/gpu/gpu_main.cc
@@ -144,6 +144,8 @@ int GpuMain(const MainFunctionParams& parameters) {
           gfx::kGLImplementationDesktopName) {
     message_loop_type = base::MessageLoop::TYPE_UI;
   }
+#elif defined(TOOLKIT_GTK)
+  message_loop_type = base::MessageLoop::TYPE_GPU;
 #elif defined(OS_LINUX)
   message_loop_type = base::MessageLoop::TYPE_DEFAULT;
 #endif