Re-land: base: Introduce an explicit call for reducing emulated discardable memory usage.

base/memory/discardable_memory_android.cc

Index: base/memory/discardable_memory_android.cc
diff --git a/base/memory/discardable_memory_android.cc b/base/memory/discardable_memory_android.cc
index 8988c2b8d2bd46d759ec2f9c42243b6274d114be..acf29ac85f11eb19df32b638048d4ded8e9990a5 100644
--- a/base/memory/discardable_memory_android.cc
+++ b/base/memory/discardable_memory_android.cc
@@ -32,10 +32,7 @@ size_t GetOptimalAshmemRegionSizeForAllocator() {
 // Holds the shared state used for allocations.
 struct SharedState {
   SharedState()
-      : manager(kAshmemMemoryLimit,
-                kAshmemMemoryLimit,
-                kAshmemMemoryLimit,
-                TimeDelta::Max()),
+      : manager(kAshmemMemoryLimit, kAshmemMemoryLimit, TimeDelta::Max()),
         allocator(kAshmemAllocatorName,
                   GetOptimalAshmemRegionSizeForAllocator()) {}
 
@@ -47,16 +44,6 @@ LazyInstance<SharedState>::Leaky g_shared_state = LAZY_INSTANCE_INITIALIZER;
 }  // namespace
 
 // static
-void DiscardableMemory::RegisterMemoryPressureListeners() {
-  internal::DiscardableMemoryEmulated::RegisterMemoryPressureListeners();
-}
-
-// static
-void DiscardableMemory::UnregisterMemoryPressureListeners() {
-  internal::DiscardableMemoryEmulated::UnregisterMemoryPressureListeners();
-}
-
-// static
 bool DiscardableMemory::ReduceMemoryUsage() {
   return internal::DiscardableMemoryEmulated::ReduceMemoryUsage();
 }