android: Make org.chromium.base.SysUtils.isLowEndDevice() work without native code.

base/android/sys_utils_unittest.cc

+// Copyright 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/android/sys_utils.h"
+
+#include <unistd.h>
+
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+namespace android {
+
+TEST(SysUtils, AmountOfPhysicalMemory) {
+  // Check that the RAM size reported by sysconf() matches the one
+  // computed by base::android::SysUtils::AmountOfPhysicalMemory().
+  size_t sys_ram_size =
+      static_cast<size_t>(sysconf(_SC_PHYS_PAGES) * PAGE_SIZE);
+  EXPECT_EQ(sys_ram_size, SysUtils::AmountOfPhysicalMemoryKB() * 1024UL);
+}
+
+}  // namespace android
+}  // namespace base