discardable_memory: Using mojo IPC to replace Chrome IPC

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 662eef67d891980a053c94f0a366a181fd76d15e..371da52ae56fb6a002fb5a37f990818e42524b2d 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -599,6 +599,7 @@ RenderThreadImpl::RenderThreadImpl(
     : ChildThreadImpl(Options::Builder()
                           .InBrowserProcess(params)
                           .AutoStartServiceManagerConnection(false)
+                          .InitDiscardableMemory(true)
                           .ConnectToBrowser(true)
                           .Build()),
       renderer_scheduler_(std::move(scheduler)),
@@ -616,6 +617,7 @@ RenderThreadImpl::RenderThreadImpl(
     : ChildThreadImpl(Options::Builder()
                           .AutoStartServiceManagerConnection(false)
                           .ConnectToBrowser(true)
+                          .InitDiscardableMemory(true)
                           .Build()),
       renderer_scheduler_(std::move(scheduler)),
       main_message_loop_(std::move(main_message_loop)),