[Reland] Post loading tasks on the appropriate WebFrameScheduler's queue

content/renderer/renderer_blink_platform_impl.cc

Index: content/renderer/renderer_blink_platform_impl.cc
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index f68ee6a942d702fc4539deeccfb52d7eb4ab7b62..bfce2bb4bce322b6cb00348d5740e24636c220db 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -237,6 +237,7 @@ RendererBlinkPlatformImpl::RendererBlinkPlatformImpl(
       sudden_termination_disables_(0),
       plugin_refresh_allowed_(true),
       default_task_runner_(renderer_scheduler->DefaultTaskRunner()),
+      loading_task_runner_(renderer_scheduler->LoadingTaskRunner()),
       web_scrollbar_behavior_(new WebScrollbarBehaviorImpl) {
 #if !defined(OS_ANDROID) && !defined(OS_WIN)
   if (g_sandbox_enabled && sandboxEnabled()) {
@@ -273,6 +274,16 @@ void RendererBlinkPlatformImpl::Shutdown() {
 
 //------------------------------------------------------------------------------
 
+scoped_refptr<base::SingleThreadTaskRunner>
+RendererBlinkPlatformImpl::LoadingTaskRunnerForCurrentThread() {
+  if (loading_task_runner_.get() &&
+      loading_task_runner_->BelongsToCurrentThread()) {
+    return loading_task_runner_;
+  } else {
+    return base::ThreadTaskRunnerHandle::Get();
+  }
+}
+
 blink::WebThread* RendererBlinkPlatformImpl::currentThread() {
   if (main_thread_->isCurrentThread())
     return main_thread_.get();