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

base/sys_info.h

Index: base/sys_info.h
diff --git a/base/sys_info.h b/base/sys_info.h
index 7ce4e659f28b989e1151dddc3cf431923768539e..d24acdf6b434eddf991c7787dc4f4e10989e9003 100644
--- a/base/sys_info.h
+++ b/base/sys_info.h
@@ -129,6 +129,11 @@ class BASE_EXPORT SysInfo {
   static int DalvikHeapSizeMB();
   static int DalvikHeapGrowthLimitMB();
 #endif  // defined(OS_ANDROID)
+
+  // Returns true if this is a low-end device.
+  // Low-end device refers to devices having less than 512M memory in the
+  // current implementation.
+  static bool IsLowEndDevice();
 };
 
 }  // namespace base