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

base/memory/discardable_memory_android.cc

 // Copyright (c) 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #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"
 #include "base/logging.h"
 #include "base/memory/discardable_memory_ashmem.h"
 #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 {
 
 const char kAshmemAllocatorName[] = "DiscardableMemoryAshmemAllocator";
 
 // For Ashmem, have the DiscardableMemoryManager trigger userspace eviction
 // when address space usage gets too high (e.g. 512 MBytes).
 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.
 struct SharedState {
   SharedState()
       : manager(kAshmemMemoryLimit, kAshmemMemoryLimit),
         allocator(kAshmemAllocatorName,
                   GetOptimalAshmemRegionSizeForAllocator()) {}
 
   internal::DiscardableMemoryManager manager;
@@ skipping 63 matching lines @@
   return scoped_ptr<DiscardableMemory>();
 }
 
 // static
 void DiscardableMemory::PurgeForTesting() {
   g_shared_state.Pointer()->manager.PurgeAll();
   internal::DiscardableMemoryEmulated::PurgeForTesting();
 }
 
 }  // namespace base