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

base/android/sys_utils.h

Index: base/android/sys_utils.h
diff --git a/base/android/sys_utils.h b/base/android/sys_utils.h
index 78122ff572d632b9fb1538c52b8696d22c34e2d3..318c75e6140cf317a960b0385fc76fdbb997da07 100644
--- a/base/android/sys_utils.h
+++ b/base/android/sys_utils.h
@@ -14,8 +14,12 @@ class BASE_EXPORT SysUtils {
  public:
   static bool Register(JNIEnv* env);
 
+  // Returns true iff this is a low-end device.
   static bool IsLowEndDevice();
 
+  // Return the device's RAM size in kilo-bytes. Used for testing.
+  static size_t AmountOfPhysicalMemoryKB();
+
  private:
   SysUtils();
 };