Re-land: base: Fix registering of memory pressure listeners used when emulating discardable memory.

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 e84132f08f94b137ce01d819f96f00e5e2279c20..7912cad652a98534a77edc8c80982a330c40773d 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -430,6 +430,10 @@ void RenderThreadImpl::Init() {
 
   base::DiscardableMemory::SetPreferredType(type);
 
+  // Allow discardable memory implementations to register memory pressure
+  // listeners.
+  base::DiscardableMemory::RegisterMemoryPressureListeners();
+
   // AllocateGpuMemoryBuffer must be used exclusively on one thread but
   // it doesn't have to be the same thread RenderThreadImpl is created on.
   allocate_gpu_memory_buffer_thread_checker_.DetachFromThread();