Revert "Don't wait for current activity to pause before resuming next."

This reverts commit cbb722ed06092a9e2be37150aa8bc635f0fe21da.
diff --git a/services/java/com/android/server/am/ActivityManagerService.java b/services/java/com/android/server/am/ActivityManagerService.java
index 7852123..8a5e7fc 100644
--- a/services/java/com/android/server/am/ActivityManagerService.java
+++ b/services/java/com/android/server/am/ActivityManagerService.java
@@ -138,7 +138,6 @@
 import java.lang.IllegalStateException;
 import java.lang.ref.WeakReference;
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Comparator;
@@ -2752,7 +2751,13 @@
         }
 
         // Just in case...
-        mMainStack.appDiedLocked(app);
+        if (mMainStack.mPausingActivity != null && mMainStack.mPausingActivity.app == app) {
+            if (DEBUG_PAUSE) Slog.v(TAG, "App died while pausing: " +mMainStack.mPausingActivity);
+            mMainStack.mPausingActivity = null;
+        }
+        if (mMainStack.mLastPausedActivity != null && mMainStack.mLastPausedActivity.app == app) {
+            mMainStack.mLastPausedActivity = null;
+        }
 
         // Remove this application's activities from active lists.
         mMainStack.removeHistoryRecordsForAppLocked(app);
@@ -6488,7 +6493,7 @@
                 mMainStack.stopIfSleepingLocked();
                 final long endTime = System.currentTimeMillis() + timeout;
                 while (mMainStack.mResumedActivity != null
-                        || mMainStack.mPausingActivities.size() > 0) {
+                        || mMainStack.mPausingActivity != null) {
                     long delay = endTime - System.currentTimeMillis();
                     if (delay <= 0) {
                         Slog.w(TAG, "Activity manager shutdown timed out");
@@ -8295,13 +8300,8 @@
         }
 
         pw.println(" ");
-        if (mMainStack.mPausingActivities.size() > 0) {
-            pw.println("  mPausingActivities: " + Arrays.toString(
-                    mMainStack.mPausingActivities.toArray()));
-        }
-        if (mMainStack.mInputPausedActivities.size() > 0) {
-            pw.println("  mInputPausedActivities: " + Arrays.toString(
-                    mMainStack.mInputPausedActivities.toArray()));
+        if (mMainStack.mPausingActivity != null) {
+            pw.println("  mPausingActivity: " + mMainStack.mPausingActivity);
         }
         pw.println("  mResumedActivity: " + mMainStack.mResumedActivity);
         pw.println("  mFocusedActivity: " + mFocusedActivity);
@@ -13876,13 +13876,7 @@
     private final ActivityRecord resumedAppLocked() {
         ActivityRecord resumedActivity = mMainStack.mResumedActivity;
         if (resumedActivity == null || resumedActivity.app == null) {
-            for (int i=mMainStack.mPausingActivities.size()-1; i>=0; i--) {
-                ActivityRecord r = mMainStack.mPausingActivities.get(i);
-                if (r.app != null) {
-                    resumedActivity = r;
-                    break;
-                }
-            }
+            resumedActivity = mMainStack.mPausingActivity;
             if (resumedActivity == null || resumedActivity.app == null) {
                 resumedActivity = mMainStack.topRunningActivityLocked(null);
             }