Use try-with-resources to avoid accidentaly leaking unclosed objects.

Try-with-resources guarantees that objects will be closed even if an
exception happens after their creation. It also handles nulls and avoids
throwing NPE.

Test: built and launched Cuttlefish.
Change-Id: I80e767d1fbbca25a724bfe94e1752f88891a6bb0

core/java/android/app/WallpaperInfo.java

@@ -96,31 +96,30 @@ public final class WallpaperInfo implements Parcelable {
             throws XmlPullParserException, IOException {
         mService = service;
         ServiceInfo si = service.serviceInfo;
-        
+
         final PackageManager pm = context.getPackageManager();
-        XmlResourceParser parser = null;
-        try {
-            parser = si.loadXmlMetaData(pm, WallpaperService.SERVICE_META_DATA);
+        try (XmlResourceParser parser = si.loadXmlMetaData(pm,
+                WallpaperService.SERVICE_META_DATA)) {
             if (parser == null) {
                 throw new XmlPullParserException("No "
                         + WallpaperService.SERVICE_META_DATA + " meta-data");
             }
-        
+
             Resources res = pm.getResourcesForApplication(si.applicationInfo);
-            
+
             AttributeSet attrs = Xml.asAttributeSet(parser);
-            
+
             int type;
-            while ((type=parser.next()) != XmlPullParser.END_DOCUMENT
+            while ((type = parser.next()) != XmlPullParser.END_DOCUMENT
                     && type != XmlPullParser.START_TAG) {
             }
-            
+
             String nodeName = parser.getName();
             if (!"wallpaper".equals(nodeName)) {
                 throw new XmlPullParserException(
                         "Meta-data does not start with wallpaper tag");
             }
-            
+
             TypedArray sa = res.obtainAttributes(attrs,
                     com.android.internal.R.styleable.Wallpaper);
             mSettingsActivityName = sa.getString(
@@ -159,8 +158,6 @@ public final class WallpaperInfo implements Parcelable {
         } catch (NameNotFoundException e) {
             throw new XmlPullParserException(
                     "Unable to create context for: " + si.packageName);
-        } finally {
-            if (parser != null) parser.close();
         }
     }