Merge 281795 "base: Add soft memory limit to DiscardableMemoryMa..."

base/memory/discardable_memory_mac.cc

Index: base/memory/discardable_memory_mac.cc
===================================================================
--- base/memory/discardable_memory_mac.cc	(revision 283285)
+++ base/memory/discardable_memory_mac.cc	(working copy)
@@ -25,7 +25,11 @@
 const size_t kMacMemoryLimit = 512 * 1024 * 1024;
 
 struct SharedState {
-  SharedState() : manager(kMacMemoryLimit, kMacMemoryLimit) {}
+  SharedState()
+      : manager(kMacMemoryLimit,
+                kMacMemoryLimit,
+                kMacMemoryLimit,
+                TimeDelta::Max()) {}
 
   internal::DiscardableMemoryManager manager;
 };
@@ -166,6 +170,11 @@
 }
 
 // static
+bool DiscardableMemory::ReduceMemoryUsage() {
+  return internal::DiscardableMemoryEmulated::ReduceMemoryUsage();
+}
+
+// static
 void DiscardableMemory::GetSupportedTypes(
     std::vector<DiscardableMemoryType>* types) {
   const DiscardableMemoryType supported_types[] = {