Set gpu memory policy in UI compositor.

ui/compositor/compositor.cc

Index: ui/compositor/compositor.cc
diff --git a/ui/compositor/compositor.cc b/ui/compositor/compositor.cc
index e2783947ffad762ea8adf17d6a4e5b99400555fb..264e2fe1920dc003ba6817e5a124385d6abbba01 100644
--- a/ui/compositor/compositor.cc
+++ b/ui/compositor/compositor.cc
@@ -166,6 +166,14 @@ Compositor::Compositor(ui::ContextFactory* context_factory,
   settings.use_compositor_animation_timelines =
       command_line->HasSwitch(switches::kUIEnableCompositorAnimationTimelines);
 
+#if !defined(OS_ANDROID)
+  // TODO(sohanjg): Revisit this memory usage in tile manager.
+  cc::ManagedMemoryPolicy policy(
+      512 * 1024 * 1024, gpu::MemoryAllocation::CUTOFF_ALLOW_NICE_TO_HAVE,
+      settings.memory_policy_.num_resources_limit);
+  settings.memory_policy_ = policy;
+#endif
+
   base::TimeTicks before_create = base::TimeTicks::Now();
 
   cc::LayerTreeHost::InitParams params;