Add account sync summary.

- Check for the number of sync adapter that is enabled for the account
and
update the summary text for the account sync preference accordingly.
- Add divider above the Remove Account button.

Bug: 62862167
Test: make RunSettingsRoboTests
Change-Id: Ic333f62cce9aed0a72771324976ebe3d8e586287

src/com/android/settings/applications/LayoutPreference.java

@@ -19,6 +19,7 @@ package com.android.settings.applications;
 import android.content.Context;
 import android.content.res.TypedArray;
 import android.support.annotation.VisibleForTesting;
+import android.support.v4.content.res.TypedArrayUtils;
 import android.support.v7.preference.Preference;
 import android.support.v7.preference.PreferenceViewHolder;
 import android.util.AttributeSet;
@@ -33,19 +34,30 @@ import com.android.settings.Utils;
 public class LayoutPreference extends Preference {
 
     private final View.OnClickListener mClickListener = v -> performClick(v);
+    private boolean mAllowDividerAbove;
+    private boolean mAllowDividerBelow;
 
     @VisibleForTesting
     View mRootView;
 
     public LayoutPreference(Context context, AttributeSet attrs) {
         super(context, attrs);
-        final TypedArray a = context.obtainStyledAttributes(
+        TypedArray a = context.obtainStyledAttributes(attrs, R.styleable.Preference);
+        mAllowDividerAbove = TypedArrayUtils.getBoolean(a, R.styleable.Preference_allowDividerAbove,
+                R.styleable.Preference_allowDividerAbove, false);
+        mAllowDividerBelow = TypedArrayUtils.getBoolean(a, R.styleable.Preference_allowDividerBelow,
+                R.styleable.Preference_allowDividerBelow, false);
+        a.recycle();
+
+        a = context.obtainStyledAttributes(
                 attrs, com.android.internal.R.styleable.Preference, 0, 0);
         int layoutResource = a.getResourceId(com.android.internal.R.styleable.Preference_layout,
                 0);
         if (layoutResource == 0) {
             throw new IllegalArgumentException("LayoutPreference requires a layout to be defined");
         }
+        a.recycle();
+
         // Need to create view now so that findViewById can be called immediately.
         final View view = LayoutInflater.from(getContext())
                 .inflate(layoutResource, null, false);
@@ -78,6 +90,8 @@ public class LayoutPreference extends Preference {
         final boolean selectable = isSelectable();
         holder.itemView.setFocusable(selectable);
         holder.itemView.setClickable(selectable);
+        holder.setDividerAllowedAbove(mAllowDividerAbove);
+        holder.setDividerAllowedBelow(mAllowDividerBelow);
 
         FrameLayout layout = (FrameLayout) holder.itemView;
         layout.removeAllViews();