Update from https://crrev.com/317530

base/memory/discardable_memory_linux.cc

Index: base/memory/discardable_memory_linux.cc
diff --git a/base/memory/discardable_memory_linux.cc b/base/memory/discardable_memory_linux.cc
index 977b029bee59c4a9155dc524a88274bc1d7319c4..670ad7ef4a48ce1fe80970af76f9754bb495cb65 100644
--- a/base/memory/discardable_memory_linux.cc
+++ b/base/memory/discardable_memory_linux.cc
@@ -19,8 +19,8 @@ bool DiscardableMemory::ReduceMemoryUsage() {
 void DiscardableMemory::GetSupportedTypes(
     std::vector<DiscardableMemoryType>* types) {
   const DiscardableMemoryType supported_types[] = {
-    DISCARDABLE_MEMORY_TYPE_EMULATED,
-    DISCARDABLE_MEMORY_TYPE_SHMEM
+    DISCARDABLE_MEMORY_TYPE_SHMEM,
+    DISCARDABLE_MEMORY_TYPE_EMULATED
   };
   types->assign(supported_types, supported_types + arraysize(supported_types));
 }