Add architecture for simulating memory pressure notifications in all processes

content/child/memory/child_memory_message_filter.h

Index: content/child/memory/child_memory_message_filter.h
diff --git a/content/child/memory/child_memory_message_filter.h b/content/child/memory/child_memory_message_filter.h
index 32e2a2a1ea0ae16240b086711ae6c75c24ee9723..bc1e665c2dabe91272806a08985280ae020eb163 100644
--- a/content/child/memory/child_memory_message_filter.h
+++ b/content/child/memory/child_memory_message_filter.h
@@ -5,6 +5,7 @@
 #ifndef CONTENT_CHILD_MEMORY_CHILD_MEMORY_MESSAGE_FILTER_H_
 #define CONTENT_CHILD_MEMORY_CHILD_MEMORY_MESSAGE_FILTER_H_
 
+#include "base/memory/memory_pressure_listener.h"
 #include "ipc/message_filter.h"
 
 namespace content {
@@ -23,6 +24,8 @@ class ChildMemoryMessageFilter : public IPC::MessageFilter {
 
  private:
   void OnSetPressureNotificationsSuppressed(bool suppressed);
+  void OnSimulatePressureNotification(
+      base::MemoryPressureListener::MemoryPressureLevel level);
 
   DISALLOW_COPY_AND_ASSIGN(ChildMemoryMessageFilter);
 };