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

base/sys_utils.cc

Index: base/sys_utils.cc
diff --git a/base/sys_utils.cc b/base/sys_utils.cc
new file mode 100644
index 0000000000000000000000000000000000000000..9e724170d25b886d066dc7bf070a6102a1355040
--- /dev/null
+++ b/base/sys_utils.cc
@@ -0,0 +1,43 @@
+// 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/sys_utils.h"
+
+#include "base/base_switches.h"
+#include "base/command_line.h"
+#include "base/sys_info.h"
+
+namespace base {
+
+#if !defined(OS_ANDROID)
+static const int LOW_MEMORY_DEVICE_THRESHOLD_MB = 512;
+
+static bool detectLowEndDevice() {
+  CommandLine* command_line = CommandLine::ForCurrentProcess();
+  if (command_line->HasSwitch(switches::kEnableLowEndDeviceMode )) {
+      return true;
+  }
+  if (command_line->HasSwitch(switches::kDisableLowEndDeviceMode)) {
+      return false;
+  }
+
+  int ramSizeKB = SysUtils::AmountOfPhysicalMemoryKB();

[willchan no longer on Chromium, 2013/12/26 19:02:39]

ram_size_kb

[ostap, 2014/01/20 08:12:24]

Done.

+  return (ramSizeKB > 0 && ramSizeKB / 1024 < LOW_MEMORY_DEVICE_THRESHOLD_MB);
+}
+
+// static
+bool SysUtils::IsLowEndDevice() {
+  static bool isLowEndDevice = detectLowEndDevice();

[willchan no longer on Chromium, 2013/12/26 19:02:39]

We disable the compiler generated locks around function local statics. This is
racy. You should use LazyInstance to fix the race.

[ostap, 2014/01/20 08:12:24]

Done.

+  return isLowEndDevice;
+}
+
+// static
+size_t SysUtils::AmountOfPhysicalMemoryKB() {
+  return SysInfo::AmountOfPhysicalMemory() / 1024;

[piman, 2014/01/08 04:41:50]

I'm not sure SysInfo::AmountOfPhysicalMemory() works in the renderer / in the
sandbox.

[ostap, 2014/01/20 08:12:24]

Should work.
At least initializeV8Common() in WebKit/Source/bindings/v8/V8Initializer.cpp
calls blink::Platform::current()->physicalMemoryMB() which calls
SysInfo::AmountOfPhysicalMemoryMB() .

+}
+#endif
+
+SysUtils::SysUtils() { }
+
+}  // namespace base