Revert of Re-land: base: Enable browser-wide discardable memory on Linux, CrOS and Windows.

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 04e278023b4d83bf518db900aa9ddd7b7c8e1931..de7112457dea7a17ce0d6483af7dc931168f1261 100644
--- a/base/memory/discardable_memory_android.cc
+++ b/base/memory/discardable_memory_android.cc
@@ -58,8 +58,8 @@
     std::vector<DiscardableMemoryType>* types) {
   const DiscardableMemoryType supported_types[] = {
     DISCARDABLE_MEMORY_TYPE_ASHMEM,
-    DISCARDABLE_MEMORY_TYPE_SHMEM,
-    DISCARDABLE_MEMORY_TYPE_EMULATED
+    DISCARDABLE_MEMORY_TYPE_EMULATED,
+    DISCARDABLE_MEMORY_TYPE_SHMEM
   };
   types->assign(supported_types, supported_types + arraysize(supported_types));
 }