[Android] Add a low-end device mode override flag

base/android/java/src/org/chromium/base/SysUtils.java

 // 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.
 
 package org.chromium.base;
 
 import java.io.BufferedReader;
 import java.io.FileReader;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
 import android.app.ActivityManager;
 import android.app.ActivityManager.MemoryInfo;
 import android.content.Context;
 import android.os.Build;
 import android.util.Log;
 
+import org.chromium.base.BaseSwitches;
+import org.chromium.base.CommandLine;
+
 /**
  * Exposes system related information about the current device.
  */
 public class SysUtils {
     // Any device that runs this or an older version of the system cannot be considered 'low-end'
     private static final int ANDROID_LOW_MEMORY_ANDROID_SDK_THRESHOLD =
             Build.VERSION_CODES.JELLY_BEAN_MR2;
 
     // A device reporting strictly more total memory in megabytes cannot be considered 'low-end'.
     private static final long ANDROID_LOW_MEMORY_DEVICE_THRESHOLD_MB = 512;
@@ skipping 63 matching lines @@
         }
 
         return 0;
     }
 
     /**
      * @return Whether or not this device should be considered a low end device.
      */
     @CalledByNative
     public static boolean isLowEndDevice() {
-        if (Build.VERSION.SDK_INT <= ANDROID_LOW_MEMORY_ANDROID_SDK_THRESHOLD) {
-            return false;
-        }
-        if (sLowEndDevice == null) {
+        while (sLowEndDevice == null) {

[bulach, 2013/11/20 16:31:12]

not quite sure why use a loop here?

[jdduke (slow), 2013/11/20 18:16:34]

Only for ease of breaking upon |sLowEndDevice| initialization. I can switch to a
simple return model instead.

+            if (CommandLine.isInitialized()) {
+                if (CommandLine.getInstance().hasSwitch(BaseSwitches.ENABLE_LOW_END_DEVICE_MODE)) {
+                    sLowEndDevice = true;
+                    break;
+                }
+                if (CommandLine.getInstance().hasSwitch(BaseSwitches.DISABLE_LOW_END_DEVICE_MODE)) {
+                    sLowEndDevice = false;
+                    break;
+                }
+            }
+
+            if (Build.VERSION.SDK_INT <= ANDROID_LOW_MEMORY_ANDROID_SDK_THRESHOLD) {
+                sLowEndDevice = false;
+                break;
+            }
+
             int ramSizeKB = amountOfPhysicalMemoryKB();
             sLowEndDevice = (ramSizeKB > 0 &&
                     ramSizeKB / 1024 < ANDROID_LOW_MEMORY_DEVICE_THRESHOLD_MB);
         }
 
         return sLowEndDevice.booleanValue();
     }
 }