Expose a low-end device mode override flags for non-android OSs as well

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 c3de3a36b3d9bac3fa8d035dd7eb8fad7891c400..3215969fef5d1ab3764625244fd3eec007092615 100644
--- a/base/memory/discardable_memory_android.cc
+++ b/base/memory/discardable_memory_android.cc
@@ -4,7 +4,6 @@
 
 #include "base/memory/discardable_memory.h"
 
-#include "base/android/sys_utils.h"
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/lazy_instance.h"
@@ -13,6 +12,7 @@
 #include "base/memory/discardable_memory_ashmem_allocator.h"
 #include "base/memory/discardable_memory_emulated.h"
 #include "base/memory/discardable_memory_malloc.h"
+#include "base/sys_info.h"
 
 namespace base {
 namespace {
@@ -26,7 +26,7 @@ const size_t kAshmemMemoryLimit = 512 * 1024 * 1024;
 size_t GetOptimalAshmemRegionSizeForAllocator() {
   // Note that this may do some I/O (without hitting the disk though) so it
   // should not be called on the critical path.
-  return base::android::SysUtils::AmountOfPhysicalMemoryKB() * 1024 / 8;
+  return base::SysInfo::AmountOfPhysicalMemory() / 8;
 }
 
 // Holds the shared state used for allocations.