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

base/android/sys_utils.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 "base/android/build_info.h"
 #include "base/sys_info.h"
 #include "jni/SysUtils_jni.h"
 
-// Any device that reports a physical RAM size less than this, in megabytes
-// is considered 'low-end'. IMPORTANT: Read the LinkerLowMemoryThresholdTest
-// comments in build/android/pylib/linker/test_case.py before modifying this
-// value.
-#define ANDROID_LOW_MEMORY_DEVICE_THRESHOLD_MB 512
-
-const int64 kLowEndMemoryThreshold =
-    1024 * 1024 * ANDROID_LOW_MEMORY_DEVICE_THRESHOLD_MB;
-
-// Only support low end device changes on builds greater than JB MR2.
-const int kLowEndSdkIntThreshold = 18;
-
-// Defined and called by JNI
-static jboolean IsLowEndDevice(JNIEnv* env, jclass clazz) {
-  return base::android::SysUtils::IsLowEndDevice();
-}
-
 namespace base {
 namespace android {
 
 bool SysUtils::Register(JNIEnv* env) {
   return RegisterNativesImpl(env);
 }
 
 bool SysUtils::IsLowEndDevice() {
-  return SysInfo::AmountOfPhysicalMemory() <= kLowEndMemoryThreshold &&
-      BuildInfo::GetInstance()->sdk_int() > kLowEndSdkIntThreshold;
+  JNIEnv* env = AttachCurrentThread();
+  return Java_SysUtils_isLowEndDevice(env);
+}
+
+size_t SysUtils::AmountOfPhysicalMemoryKB() {
+  JNIEnv* env = AttachCurrentThread();
+  return static_cast<size_t>(Java_SysUtils_amountOfPhysicalMemoryKB(env));
 }
 
 SysUtils::SysUtils() { }
 
 }  // namespace android
 }  // namespace base