Add a configuration option to turn on the screen when you unplug the device.

Bug: 3068624
Change-Id: I7366ece2528b31feee920f4600a475e81a0f3709

services/java/com/android/server/PowerManagerService.java

@@ -245,6 +245,7 @@ class PowerManagerService extends IPowerManager.Stub
     private int[] mButtonBacklightValues;
     private int[] mKeyboardBacklightValues;
     private int mLightSensorWarmupTime;
+    boolean mUnplugTurnsOnScreen;
     private int mWarningSpewThrottleCount;
     private long mWarningSpewThrottleTime;
 
@@ -366,8 +367,12 @@ class PowerManagerService extends IPowerManager.Stub
                     // user activity when screen was already on.
                     // temporarily set mUserActivityAllowed to true so this will work
                     // even when the keyguard is on.
+                    // However, you can also set config_unplugTurnsOnScreen to have it
+                    // turn on.  Some devices want this because they don't have a
+                    // charging LED.
                     synchronized (mLocks) {
-                        if (!wasPowered || (mPowerState & SCREEN_ON_BIT) != 0) {
+                        if (!wasPowered || (mPowerState & SCREEN_ON_BIT) != 0 ||
+                                mUnplugTurnsOnScreen) {
                             forceUserActivityLocked();
                         }
                     }
@@ -526,6 +531,9 @@ class PowerManagerService extends IPowerManager.Stub
 
         Resources resources = mContext.getResources();
 
+        mUnplugTurnsOnScreen = resources.getBoolean(
+                com.android.internal.R.bool.config_unplugTurnsOnScreen);
+
         // read settings for auto-brightness
         mUseSoftwareAutoBrightness = resources.getBoolean(
                 com.android.internal.R.bool.config_automatic_brightness_available);