Don't poke user activity when unplugging unless screen is already on.

Change-Id: I5a5f233541e13b3a916ad0d8b3bf8d6fb49ab7fd
BUG: 1317687

Signed-off-by: Mike Lockwood <lockwood@android.com>
diff --git a/services/java/com/android/server/PowerManagerService.java b/services/java/com/android/server/PowerManagerService.java
index d3efa12..11b966e 100644
--- a/services/java/com/android/server/PowerManagerService.java
+++ b/services/java/com/android/server/PowerManagerService.java
@@ -349,10 +349,14 @@
                     // treat plugging and unplugging the devices as a user activity.
                     // users find it disconcerting when they unplug the device
                     // and it shuts off right away.
+                    // to avoid turning on the screen when unplugging, we only trigger
+                    // user activity when screen was already on.
                     // temporarily set mUserActivityAllowed to true so this will work
                     // even when the keyguard is on.
                     synchronized (mLocks) {
-                        forceUserActivityLocked();
+                        if (!wasPowered || (mPowerState & SCREEN_ON_BIT) != 0) {
+                            forceUserActivityLocked();
+                        }
                     }
                 }
             }