Pending tasks in a message loop should be deleted before shutting down Blink

content/renderer/render_thread_impl.cc

Index: content/renderer/render_thread_impl.cc
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 3b2ff69cf48366cb6fcdfae4420f3a28611dd66c..1df46e9c7a671fcf1e720e24a441350f503061c0 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -401,6 +401,13 @@ RenderThreadImpl::RenderThreadImpl(const std::string& channel_name)
   Init();
 }
 
+RenderThreadImpl::RenderThreadImpl(
+    scoped_ptr<base::MessageLoop> main_message_loop)
+    : ChildThread(Options(ShouldUseMojoChannel())),
+      main_message_loop_(main_message_loop.Pass()) {
+  Init();
+}
+
 void RenderThreadImpl::Init() {
   TRACE_EVENT_BEGIN_ETW("RenderThreadImpl::Init", 0, "");
 
@@ -657,6 +664,12 @@ void RenderThreadImpl::Shutdown() {
 
   main_thread_compositor_task_runner_ = NULL;
 
+  gpu_channel_ = NULL;
+
+  // Shut down the message loop before shutting down Blink.
+  // This prevents a scenario where a pending task in the message loop accesses
+  // Blink objects after Blink shuts down.
+  main_message_loop_.reset();
   if (webkit_platform_support_)
     blink::shutdown();