cc: Add image decode queue functionality to image manager.

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index 4ad721969aec975970d6038b239e51a6c5865d82..222759de05d8e029a6026ea1377dd0fee6ab8e25 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -207,6 +207,9 @@ Compositor::Compositor(ui::ContextFactory* context_factory,
   params.settings = &settings;
   params.main_task_runner = task_runner_;
   params.mutator_host = animation_host_.get();
+  // TODO(vmpstr): For now, we don't need a task runner in the UI since we don't
+  // use image queue here.
+  params.image_worker_task_runner = nullptr;
   host_ = cc::LayerTreeHostInProcess::CreateSingleThreaded(this, &params);
   UMA_HISTOGRAM_TIMES("GPU.CreateBrowserCompositor",
                       base::TimeTicks::Now() - before_create);