Use DiscardableMemoryManager on Android.

base/memory/discardable_memory.h

Index: base/memory/discardable_memory.h
diff --git a/base/memory/discardable_memory.h b/base/memory/discardable_memory.h
index 53d8d0e6f7c40b6b5d8d690a46b15158c4b4c0a5..9189b5eb027901a0e6e22d87853cd928b0c9fb4b 100644
--- a/base/memory/discardable_memory.h
+++ b/base/memory/discardable_memory.h
@@ -17,7 +17,7 @@ namespace base {
 
 enum DiscardableMemoryType {
   DISCARDABLE_MEMORY_TYPE_NONE,
-  DISCARDABLE_MEMORY_TYPE_ANDROID,
+  DISCARDABLE_MEMORY_TYPE_ASHMEM,
   DISCARDABLE_MEMORY_TYPE_MAC,
   DISCARDABLE_MEMORY_TYPE_EMULATED,
   DISCARDABLE_MEMORY_TYPE_MALLOC
@@ -115,10 +115,6 @@ class BASE_EXPORT DiscardableMemory {
 
   // Testing utility calls.
 
-  // Check whether a purge of all discardable memory in the system is supported.
-  // Use only for testing!
-  static bool PurgeForTestingSupported();
-
   // Purge all discardable memory in the system. This call has global effects
   // across all running processes, so it should only be used for testing!
   static void PurgeForTesting();