Use DiscardableMemoryManager on Android.

base/memory/discardable_memory_unittest.cc

Index: base/memory/discardable_memory_unittest.cc
diff --git a/base/memory/discardable_memory_unittest.cc b/base/memory/discardable_memory_unittest.cc
index d4c295565508171dc471fbf07df535609523275e..dc0e2cd21262b4d7da8dd3edb891b91bb8f2d5b7 100644
--- a/base/memory/discardable_memory_unittest.cc
+++ b/base/memory/discardable_memory_unittest.cc
@@ -47,7 +47,7 @@ TEST_P(DiscardableMemoryTest, IsNamed) {
 
 bool IsNativeType(DiscardableMemoryType type) {
   return
-      type == DISCARDABLE_MEMORY_TYPE_ANDROID ||
+      type == DISCARDABLE_MEMORY_TYPE_ASHMEM ||
       type == DISCARDABLE_MEMORY_TYPE_MAC;
 }
 
@@ -91,11 +91,8 @@ TEST_P(DiscardableMemoryTest, DeleteWhileLocked) {
   ASSERT_TRUE(memory);
 }
 
-#if !defined(OS_ANDROID)
 // Test forced purging.
 TEST_P(DiscardableMemoryTest, Purge) {
-  ASSERT_TRUE(DiscardableMemory::PurgeForTestingSupported());
-
   const scoped_ptr<DiscardableMemory> memory(CreateLockedMemory(kSize));
   ASSERT_TRUE(memory);
   memory->Unlock();
@@ -103,7 +100,6 @@ TEST_P(DiscardableMemoryTest, Purge) {
   DiscardableMemory::PurgeForTesting();
   EXPECT_EQ(DISCARDABLE_MEMORY_LOCK_STATUS_PURGED, memory->Lock());
 }
-#endif  // !OS_ANDROID
 
 #if !defined(NDEBUG) && !defined(OS_ANDROID)
 // Death tests are not supported with Android APKs.